Biomedical subjects
Publications and source records attributed to P Fleming.
Increased use of fluoroscopy during flexible bronchoscopy has raised concerns about radiation safety of health care workers in the bronchoscopy suite. We review the potential health risks associated with occupational radiation exposure, the monitoring devices available, and discuss the measures to reduce radiation exposure during flexible bronchoscopy.
AIM: Epidemiological studies suggest that pacifier use may be protective against SIDS but little is known of the relationship between pacifier use and other forms of non-nutritive sucking (NNS) in infancy, or of patterns of NNS during the night, when most SIDS deaths occur. We report the first longitudinal study of NNS by direct overnight observations in healthy infants in a sleep laboratory. METHODS: Healthy, breast fed term infants (n = 10) were enrolled at birth, and sequential overnight polygraphic and infrared video recordings of infants with their mothers performed at monthly intervals from 1 to 5 months. Each month, mother baby pairs were randomized to 1 night bed-sharing (BN) then 1 room-sharing (RN), or vice versa. 'Episodes' of pacifier, own digit and mother's digit sucking (> 1 min) were identified and compared with state-matched control periods without sucking or feeding before and after each such episode. RESULTS: 329 episodes of NNS were identified in 749 h of video recording. The prevalence of pacifier sucking decreased with age, whilst digit sucking increased. Routine pacifier users rarely sucked their digits. There were temporal differences throughout the night in the distribution of different types of sucking and in infant state during and around sucking episodes. Sleeping in the 'non-routine' location was associated with a larger percentage of nights with sucking episodes and increased sleep latency. Bed sharing (routinely or on a given night) was associated with less sucking behavior and more breastfeeding. Non-nutritive sucking was not, however, associated with decreased total time breastfeeding per night or number of feeds per night. CONCLUSION: Patterns of NNS during the night change with age and are affected by maternal proximity. Digit sucking has state modulating effects, and may be suppressed by pacifier use. Thus any benefits of pacifier use must be set against the potential loss of a self-directed ability to modulate state during the night, and possible shortening of breastfeeding duration.
OBJECTIVE: To evaluate the long-term outcome in children who had an artificial urinary sphincter (AUS) placed, after a minimum of 10 years of follow-up. PATIENTS AND METHODS: The medical records of patients who had an AUS placed at the Children's Hospital of Michigan were reviewed and a telephone questionnaire was then completed by all patients with an AUS currently in place. RESULTS: Forty-seven children initially had an AUS placed between October 1978 and August 1986; medical records and follow-up were available for 32. After a mean follow-up of 15.4 years, 13 patients had had the AUS removed and 19 currently have an intact AUS. Erosion or infection was responsible for all AUS removals. Possible risk factors for AUS removal were prior AUS erosion, prior bladder neck surgery and a balloon pressure of >70 cmH2O. Eighteen of 19 patients with an intact AUS are dry and seven void volitionally. Revision was the most common reason for additional surgery, but the revision rate has decreased with the most current AS-800 model, to 0.03 revisions per patient-year. Of the 13 patients with an AS-800 model placed after 1987, nine have not required revision. Upper tract changes were mild and uncommon. CONCLUSION: The AUS is a durable and effective surgical option in the management of neurogenic urinary incontinence, and is the only reliable technique that can preserve volitional voiding. With technical improvements to the AUS and a longer follow-up, the revision rate has decreased. Causes of AUS removal may be preventable with improvements in surgical technique and patient selection. AUS placement should be considered as a first choice for the surgical management of neurogenic sphincteric incompetence.
PURPOSE: We assessed the long-term functional, social and psychosexual outcome in children who underwent vaginal reconstruction. MATERIALS AND METHODS: We interviewed and assessed the psychological development of 16 women 17 to 28 years old (mean age 22) who underwent vaginal reconstruction only or in combination with other urogenital reconstructive procedures at ages 11 months to 18 years (mean 8.8). Psychological measures included the Beck Depression Inventory, Draw-a-Person test and Linkowski acceptance of disability scale as well as a standard questionnaire evaluating the sexual adjustment, social adjustment and ability for self-support of these women. RESULTS: Mean Beck Depression Inventory was 8.5 with less than 9 defined as minimal depression. Mean acceptance of disability score was 83.9 (range 54 to 94), indicating that patients were well adjusted with respect to the disability. Functionally 10 women were satisfied with the appearance of the vagina, 4 were neutral and 2 were dissatisfied. A total of 12 patients had no doubts about their female identity but 2 had occasional, 1 had significant and 1 had chronic doubts. Of the 16 patients 12 have completed high school, 3 are still in high school and 1 has withdrawn from high school. Of the 12 women who have completed high school 9 are currently in college and 3 have completed college. Socially all 16 participants rated family relationships as good and 13 were at least satisfied with their social life. Of the 16 women 12 have had a sexual encounter, including 1 who did not achieve orgasm. Six women are involved in long-term relationships, of whom 1 is married. In regard to the future all patients believe that they will be independent and financially stable with a fulfilling career. CONCLUSIONS: While women who have undergone vaginal reconstruction may be at risk for avoiding interpersonal relationships and sexual intimacy, we did not note this finding in our series. The majority of these patients were well adjusted to their physical condition, and had a high level of education and a stable family life.
Chemokines are important mediators of the early inflammatory response to infection and modify a wide range of host immune responses. Functional homologs of cellular chemokines have been identified in a number of herpesviruses, suggesting that the subversion of the host chemokine response contributes to the pathogenesis of these viruses. Transcriptional and reverse transcription-PCR analyses demonstrated that the murine cytomegalovirus (MCMV) chemokine homolog, m131, was spliced at the 3' end to the adjacent downstream open reading frame, m129, resulting in a predicted product of 31 kDa, which is significantly larger than most known chemokines. The in vivo impact of m131/129 was investigated by comparing the replication of MCMV mutants having m131/129 deleted (Deltam131/129) with that of wild-type (wt) MCMV. Our studies demonstrate that both wt and Deltam131/129 viruses replicated to equivalent levels during the first 2 to 3 days following in vivo infection. However, histological studies demonstrated that the early inflammatory response elicited by Deltam131/129 was reduced compared with that of wt MCMV. Furthermore, the Deltam131/129 mutants failed to establish a high-titer infection in the salivary glands. These results suggest that m131/129 possesses proinflammatory properties in vivo and is important for the dissemination of MCMV to or infection of the salivary gland. Notably, the Deltam131/129 mutants were cleared more rapidly from the spleen and liver during acute infection compared with wt MCMV. The accelerated clearance of the mutants was dependent on NK cells and cells of the CD4(+) CD8(+) phenotype. These data suggest that m131/129 may also contribute to virus mechanisms of immune system evasion during early infection, possibly through the interference of NK cells and T cells.
A case of intracoronal resorption in a recently erupted mandibular canine in an 11-year-old girl is presented. Possible aetiology and approaches to treatment of such lesions are discussed.
OBJECTIVE: To assess the prevalence of pacifier use and whether this habit adversely affects the health of 6-month-old infants. DESIGN: Data collected via self-completion questionnaires from mothers forming part of the prospective, population-based Avon Longitudinal Study of Pregnancy and Childhood. METHODS: The mothers of 10 950 infants gave information on their child's use of a pacifier at 4 weeks and 6 months of age and the presence of specific health symptoms. Adjusted logistic regression was performed to identify any associations between pacifier use and ill health. RESULTS: Two thirds of the sample had been given a pacifier at some point, with 42% being reported as having one at both ages. Younger, lower educated mothers, mothers who smoked, those living in council and overcrowded accommodation, and those reporting financial difficulties were significantly more likely to give their infant a pacifier. Pacifier use was associated significantly with a higher risk of symptoms such as wheezing, earache, vomiting, fever, diarrhea, and colic as well as with the general practitioner being called to the home and hospital admission. CONCLUSIONS: Although significant differences exist in the risk of experiencing several health symptoms between infants who do and infants who do not use a pacifier, stronger and more detailed evidence is required before recommendations can be made to discourage the use of pacifiers based purely on reducing occurrences of these symptoms.
Retinoic acid (RA), a derivative of vitamin A, plays a critical role as a signaling molecule in axial patterning of vertebrates. Here we report that RA exposure of zebrafish (Danio rerio) and mummichog (Fundulus heteroclitus) embryos during gastrulation results in homeotic duplications of the pectoral fins in up to 94% of fish. We have observed three to four pairs of fins in an individual fish. Although some duplications are partial, many represent complete axial duplications of the pectoral girdle and fin and include coracoscapulae, proximal radials, and dermal fin elements. Fin duplications are observed only at a defined dose of RA. Inhibition of RA synthesis by exposure to citral during a narrow developmental window leads to fish which lack pectoral fins but can be rescued by addition of exogenous RA, suggesting that RA signaling is critical to fin specification during early development. The ability to consistently induce multiple fins in a large number of vertebrate embryos should contribute to the understanding of genetic regulation of the normal positioning of limbs during embryogenesis.
OBJECTIVE: To assess whether the recommendations that infants sleep supine could have adverse consequences on their motor and mental development. DESIGN: A prospective study of infants, delivered before, during, and after the Back to Sleep Campaign in the United Kingdom, followed to 18 months of age. SUBJECTS: The children were participants of the Avon Longitudinal Study of Pregnancy and Childhood born to mothers resident in the three former Bristol-based health districts of Avon, with expected date of delivery from April 1, 1991 to December 31, 1992. Questionnaires were completed on sleeping position at 4 to 6 weeks of age and sets of standardized questions on development at 6 and 18 months. MAIN OUTCOME MEASURES: Social, communication, fine and gross motor, and total developmental scales based on the Denver Developmental Screening Test at 6 and 18 months. RESULTS: After adjustment for 27 factors using multiple regression, 3 of the 10 scales and subscales significantly distinguished between front and back sleeping position. At 6 months of age, infants put to sleep on their front had a mean score 0.38 SD (95% confidence interval [CI]: 0.28, 0.49) higher on the gross motor scale, 0.11 SD (95% CI: 0.00, 0.23) higher in the social skills scale, and a total development score 0.20 SD (95% CI: 0.10, 0.30) higher than those on their backs. These differences were no longer apparent at 18 months. CONCLUSIONS: There is some evidence that putting infants to sleep in the supine position results in a reduced developmental score at 6 months of age, but this disadvantage appears to be transient. Weighing this against the adverse health effects demonstrated with the prone sleeping position, these results should not change the message of the Back to Sleep Campaign.
Embryonic levels of retinoic acid (RA) and the response of cells to RA are critical to the normal development of vertebrates. To understand the effects of RA signaling in Fundulus heteroclitus, we exposed embryos to a range of RA concentrations of 2 h during gastrulation. Embryos exposed to low concentrations of RA (10(-10)-10(-7) M) develop normally, whereas those exposed to higher concentrations (5 x 10(-7)-10(-4) M) develop characteristic dose-dependent defects. We describe, in detail, four stages of development that represent morphological effects of RA on (1) cell death and defects in the brain, heart, and eye, (2) relative size and differentiation, (3) duplications of pectoral fins, and (4) deletions in craniofacial cartilage elements. Analysis of cartilaginous skeletal elements demonstrates distinct patterns of deletions in the neurocranium and pharyngeal skeleton in response to increasing concentrations of RA. In F. heteroclitus, RA treatment during gastrulation results in five highly consistent phenotypes, which we have incorporated into an index of embryonic RA defects. This index should be valuable in the genetic analysis of RA pathways and in evaluating chemicals that interfere with embryonic RA signaling.
Children who present with extensive fractures of anterior teeth pose a difficult clinical problem. Pulpal and periodontal injuries must be carefully assessed and managed. Rapid restoration of the form and contour of the extensively fractured tooth is advisable, not only to improve esthetics but also to prevent unwanted tipping or tilting of adjacent teeth and overeruption of opposing teeth. A modified Essix retainer, simply constructed in the laboratory, can be used to provisionally restore the extensively fractured anterior tooth.
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Herpesviruses, such as murine and human cytomegalovirus (MCMV and HCMV), can establish a persistent infection within the host and have diverse mechanisms as protection from host immune defences. Several herpesvirus genes that are homologous to host immune modulators have been identified, and are implicated in viral evasion of the host immune response. The discovery of a viral major histocompatibility complex (MHC) class I homologue, encoded by HCMV, led to speculation that it might function as an immune modulator and disrupt presentation of peptides by MHC class I to cytotoxic T cells. However, there is no evidence concerning the biological significance of this gene during viral infection. Recent analysis of the MCMV genome has also demonstrated the presence of a MHC class I homologue. Here we show that a recombinant MCMV, in which the gene encoding the class I homologue has been disrupted, has severely restricted replication during the acute stage of infection compared with wild-type MCMV. We demonstrate by in vivo depletion studies that natural killer (NK) cells are responsible for the attenuated phenotype of the mutant. Thus the viral MHC class I homologue contributes to immune evasion through interference with NK cell-mediated clearance.
OBJECTIVE: To assess whether the recommendations that infants sleep supine could have adverse health consequences. DESIGN: A prospective study of infants, delivered before, during, and after the Back to Sleep Campaign in the United Kingdom (UK), followed to 6 months of age. The children were part of the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC). Subjects. Singletons born to mothers resident in the three former Bristol-based health districts of Avon in the period June 1991 to December 1992, and for whom questionnaires were completed on sleeping position at 4 to 6 weeks of age (n = 9777); for these infants 8524 questionnaires were also completed at 6 to 8 months of age. MAIN OUTCOME MEASURES: Subjective measures of health, the presence of specific signs and symptoms, duration of sleep at night, and calling the family doctor to the home. RESULTS: Of 43 outcomes considered, after adjustment for 12 factors using logistic regression only 2 were associated with raised risk among infants put to sleep on their back (diaper rash and cradle cap). Infants put to sleep prone had increased risk of a number of health outcomes, including cough and possibly pyrexia. CONCLUSIONS: There is no evidence that putting infants to sleep in the supine position results in increased morbidity, although changes in prevalence of rare disorders would not have been identified.
Functional effects of fetal hippocampal field grafts were assessed in rats with spatial learning and memory impairments following global cerebral ischaemia. Experiment 1 examined effects of grafts dissected from fields CA1 and CA3 at embryonic day 19 and from the dentate gyrus at postnatal day 1. Cell suspensions (15,000 cells/site) were implanted bilaterally at two points above the dorsal CA1 area two weeks after four-vessel occlusion (electrocoagulation of the vertebral arteries followed the 24 h later by occlusion of the carotid arteries for 15 min). Histological examination showed that CA1 neuronal loss (60-70%) was equivalent in all ischaemic groups and that 80% of CA1 and 60% of CA3 grafts survived and were sited appropriately in the alveus or corpus callosum above the area of ischaemic CA1 damage in the host, but there was no survival of dentate grafts. Results from rats with poor pyramidal cell graft survival were excluded, but those from rats with non-surviving dentate grafts were retained as an additional control group. Acquisition in the water maze was examined nine and 25 weeks after transplantation, and spatial working memory was assessed in three-door runway and water maze matching-to-position tasks 19 and 28 weeks after grafting, respectively. For water maze acquisition rats were trained with two trails/day and a 10 min inter-trial interval for 10-12 days to locate a submerged platform. Ischaemic rats with CA1 grafts learned the platform position as rapidly as non-ischaemic controls, searched appropriately in the training quadrant and were accurate in heading towards the platform, but were initially impaired on recall of the precise platform position on probe trials with the platform removed. Performance of ischaemic controls and groups with CA3 and non-surviving dentate graft groups was significantly impaired relative to controls and to the CA1 grafted group. The CA1 grafted group was also as successful as controls in matching-to-position in the water maze and substantially superior to the other ischaemic groups, assessed using three trials/day, with a 30-s inter-trial interval and a different platform position on each day. In a more complex matching-to-position task in the three-door runway, the performance of the CA1 grafted group was significantly impaired relative to controls, although superior to that of the other ischaemic control and graft groups. Functional recovery with CA1, but not CA3, grafts in ischaemic rats was replicated in a second experiment which assessed water maze acquisition and working memory at 10 and 14 weeks after transplantation, in rats with 90% graft survival. These results indicate that long-lasting, task-dependent improvements can be seen in ischaemic rats with CA1 fetal grafts in both aversively and appetitively motivated spatial learning tasks. The findings suggest that functional recovery requires homotypic replacement of CA1 cells damaged by ischaemia, rather than provision of structurally similar glutamate-releasing CA3 pyramidal cells.
Bereaved parents' perceptions of care after the sudden, unexpected death of their child (from 1 week to 12 years), and the care that was or could be offered by statutory and voluntary agencies, was assessed in 11 health districts in seven regions of England and Wales. In these 11 districts, 185 families were identified who met the criteria of the study. Permission to contact these families was given by only 72 general practitioners. Of these, 42 families responded (58%). Sudden infant death syndrome accounted for 43% of the deaths. The results from postal questionnaires sent to both parents showed that hospital care was perceived as good on the whole, although parents would like more choices. Most parents felt that community care was inadequate, leaving many feeling isolated. In contrast, questionnaires from health visitors and general practitioners in the same health districts showed that they believed that they were the most appropriate professionals to give follow up care, but as there were few policies to guide them and little training provided, felt unable to offer support.
PURPOSE: We evaluated the clinical use of long-term intravesical oxybutynin chloride in the treatment of neurogenic bladder dysfunction in children with myelodysplasia who could not tolerate oral anticholinergics. MATERIALS AND METHODS: We retrospectively reviewed the records of all patients recommended for intravesical oxybutynin chloride therapy. A total of 12 girls and 18 boys 1 to 17 years old was recruited for study. Oxybutynin chloride (5 mg.) was instilled 2 times daily and pretreatment cystograms were compared to followup urodynamic studies. Duration of therapy was 2 to 26 months (mean 13, median 12). RESULTS: Mean total capacity plus or minus standard deviation increased from 209 +/- 103 to 282 +/- 148 ml. (p < 0.01), mean safe capacity increased from 157 +/- 105 to 234 +/- 147 ml. (p < 0.01) and mean age adjusted safe capacity increased from 76 +/- 36 to 115 +/- 62%. Of the 29 patients who were incontinent 3 (10%) achieved continence and 19 (65%) reported a decreased use of sanitary pads. None of the patients had systemic side effects related to intravesical treatment. CONCLUSIONS: We believe that intravesical oxybutynin chloride is a viable treatment option for patients with myelodysplasia in whom oral therapy fails.
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