Biomedical subjects
J Neilson
Publications and source records attributed to J Neilson.
Monitoring the duration of antigen-receptor occupancy by calcineurin/glycogen-synthase-kinase-3 control of NF-AT nuclear shuttling.
Recent structural studies have supported a kinetic model of TCR activation, raising the question of how the duration of receptor occupancy is translated into activation of immune response genes. We summarize evidence that the cytoplasmic-to-nuclear shuttling of NF-ATc family members monitors the duration of receptor occupancy.
Effective care in pregnancy and childbirth: a synopsis.
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Antibiotics for preterm premature rupture of membranes.
OBJECTIVES: The aim of the review was to evaluate the effectiveness and the immediate and long-term safety of the effects of administering antibiotics to women with preterm prelabour rupture of membranes on maternal infectious morbidity, fetal and neonatal morbidity and mortality, and longer term childhood development. SEARCH STRATEGY: All randomized trials identified using the search strategy described by the Cochrane Pregnancy and Childbirth Group. SELECTION CRITERIA: All trials which reported clinically relevant outcomes (as opposed to laboratory data) were included. DATA COLLECTION AND ANALYSIS: Data were extracted from each report without any blinding of either the results or the treatments which women received. Unpublished data were sought from a number of authors. MAIN RESULTS: Antibiotic treatment following pPROM is effective at prolonging pregnancy and reducing maternal and neonatal infectious morbidity. There is no statisically proven benefit that their use improves neonatal mortality and morbidity in the short or long term. REVIEWER'S CONCLUSIONS: There are insufficient data to recommend routine prescription of antibiotics in this clinical situation. Research into this area should continue.
Ultrasound screening in pregnancy: a systematic review of the clinical effectiveness, cost-effectiveness and women's views.
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More studies are needed before giving magnesium sulphate for pre-eclampsia.
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The sequential analysis of trisomy 12 in B-cell chronic lymphocytic leukaemia.
In this longitudinal study we evaluated the clinical significance of screening for trisomy 12 by fluorescence in situ hybridization (FISH) and correlated these findings with survival, disease progression and need for treatment. Interphase FISH was performed on 85 patients in 1993/94 and repeated on 41 patients in 1996/97. Over the 4-year period there was no significant change in the percentage of trisomic cells, even in patients with disease progression. Overall survival and requirement for treatment were similar for patients with and without FISH-defined trisomy 12.
Studies of human immunodeficiency virus type 1 mucosal viral shedding and transmission in Kenya.
If human immunodeficiency virus type 1 (HIV-1) vaccines are to be highly effective, it is essential to understand the virologic factors that contribute to HIV-1 transmission. It is likely that transmission is determined, in part, by the genotype or phenotype (or both) of infectious virus present in the index case, which in turn will influence the quantity of virus that may be exchanged during sexual contact. Transmission may also depend on the fitness of the virus for replication in the exposed individual, which may be influenced by whether a virus encounters a target cell that is susceptible to infection by that specific variant. Of interest, our data suggest that the complexity of the virus that is transmitted may be different in female and male sexual exposures.
Oncogenes and tumour suppressor genes in first trimester human fetal gonadal development.
Tumour suppressor genes and oncogenes that control proliferation and apoptosis are known to play an important role in embryogenesis, second trimester fetal oocyte loss, adult ovulation, and in adult male testicular degeneration. We have examined tumour suppressor genes, oncogenes and oestrogen receptors during first trimester human gonadal differentiation to investigate their role at this crucial phase in development. Immunohistochemistry was used to localize the gene products of Bcl-2, c-erB-2, c-myc, p53, nm23 and oestrogen receptor. As gonadal development occurred at 6-12 weeks gestation, a changing pattern of expression was observed that varied in different cell types. The oestrogen receptor was not present in oogonia, spermatogonia and supporting cells during the first trimester. This study highlights the importance of oncogenes and tumour suppressor genes in first trimester gonadal development.
Reduced heart rate variability following repair of tetralogy of Fallot.
OBJECTIVE: To examine autonomic function as assessed by heart rate variability in patients 10 or more years after repair of tetralogy of Fallot, and to relate this to cardiac structure, function, and electrocardiographic indices. METHODS: Heart rate variability was measured by standard time domain techniques on a 24 hour Holter ECG in 28 patients, aged 12 to 34 years (mean 19.5), who had undergone repair of tetralogy of Fallot at least 10 years previously. Echocardiography was performed to assess left ventricular size and function, right ventricular size and pressure, and any proximal pulmonary arterial stenosis. Right ventricular function was evaluated by radionuclide scan. QRS duration, QT interval, and QT dispersion were measured on a standard 12 lead ECG. Measurements of heart rate variability were compared with values from 28 age matched healthy controls (mean age 19.9 years). Interrelations between variables were assessed using Pearson correlation coefficients and stepwise regression analysis. RESULTS: Heart rate variability was reduced, compared with values for age matched normal controls, in 12 of the 28 patients. Reduced heart rate variability was associated with increased age, increased right ventricular size and pressure, and widening of the QRS complex. CONCLUSIONS: Reduced heart rate variability is a feature following repair of tetralogy of Fallot. It is associated with increasing age, impaired right ventricular haemodynamics, and widening of the QRS complex. Under these circumstances, reduced heart rate variability may be a marker for deteriorating right ventricular function. Increased QRS duration has been identified as a risk factor for sudden death following repair of tetralogy of Fallot, and impaired cardiac autonomic control may be one of the mechanisms involved.
Therapeutic actions of L-deprenyl in dogs: a model of human brain aging.
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Second trimester serum free beta human chorionic gonadotrophin levels as a predictor of pre-eclampsia.
BACKGROUND: To prospectively assess maternal serum free beta human chorionic gonadotrophin (beta hCG) estimation between 15 and 18 weeks gestation, as a screening test for pre-eclampsia in primigravid women. METHODS: A prospective longitudinal study in a University Teaching Hospital. The study population was 430 primigravid women, who had maternal serum free beta hCG levels measured as part of antenatal serum screening for Down's Syndrome in the second trimester, who booked consecutively within the unit and went on to deliver on the unit's labor ward. These women were followed during their subsequent pregnancy and categorized into those who remained normotensive and those who developed pre-eclampsia on both clinical and biochemical grounds. The beta hCG levels were used to construct a receiver operator characteristics curve (ROC) to assess the screening potential for pre-eclampsia. RESULTS: Nineteen (4.4%) women in the study group developed pre-eclampsia. The median second trimester free beta hCG multiples of the median (MOM) was significantly elevated compared to that of the control group (1.52 vs 1.10, p=0.03). The ROC curve shows that for a sensitivity of 79%, the specificity was only 54%. CONCLUSIONS: Maternal serum free beta hCG alone measured in the second trimester is not clinically useful as a screening test for pre-eclampsia in primigravid women. It has, however, some predictive value.
Magnesium sulphate in the treatment of eclampsia and pre-eclampsia: an overview of the evidence from randomised trials.
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Hepatitis G virus in long-term survivors of haematological malignancy.
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Cardiotocography during labour.
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Monitoring for central apnoea in infancy--limitations of single channel recordings.
Apparent central apnoea (absent breathing movements) detected by monitoring movement of the thoracic wall was compared with simultaneous detection by abdominal wall movement. Eighteen infants provided one or more 24 hour recording of heart rate (electrocardiography), thoracic respiration (transthoracic impedance), and abdominal wall movement (pressure sensitive capsule distortion). Detection of true apnoea, recognition of artefact, and measurement of the duration of true apnoea were all improved when two channels of respiratory monitoring were used in combination. We recommend that any study purporting to observe breathing patterns by indirect recording of respiratory movement will be more reliable if more than one channel of respiratory movements is recorded simultaneously. Further, in infants no estimation of duration of central apnoea can be made on the basis of either a transthoracic impedance record alone or an abdominal wall movement sensor alone. Comparison of findings among studies using different single channel recordings are unlikely to be meaningful.
Intoxication of two dogs by fruit of Brunfelsia australis.
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