359 results on '"Cowan, F. M."'
Search Results
152. Developing complex interventions for rigorous evaluation--a case study from rural Zimbabwe.
- Author
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Power R, Langhaug LF, Nyamurera T, Wilson D, Bassett MT, and Cowan FM
- Subjects
- Adolescent, Cultural Characteristics, Feasibility Studies, Female, Humans, Male, Randomized Controlled Trials as Topic, Rural Population, Zimbabwe, Family Planning Services, Health Education organization & administration, Research Design
- Abstract
Much attention has been placed on the need to develop and evaluate complex interventions targeting public health issues, such as reproductive health. However, and as has been the case in the recent past, even well-designed trials will be flawed unless meticulous attention is paid to ensuring the most appropriate intervention is designed and developed. This requires a well-resourced and carefully planned feasibility study, incorporating both formative and process evaluation, with particular attention being paid to the context of the proposed intervention. In this paper, we describe the way in which a feasibility study helped redesign and shape a complex intervention targeting adolescent sexual health in rural Zimbabwe. By using a mixture of in-depth interviews, focus groups and participant observation with pupils, parents, teachers and education officers, we were able to show that the intervention as originally conceived was unlikely to be deliverable. Process evaluation findings from the feasibility study led to substantial changes to both the content and delivery of the proposed intervention, which is now subject to testing for effectiveness in a large community randomized trial.
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- 2004
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153. Gastrointestinal manifestations of postnatal cytomegalovirus infection in infants admitted to a neonatal intensive care unit over a five year period.
- Author
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Cheong JL, Cowan FM, and Modi N
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- Cytomegalovirus Infections epidemiology, Female, Gastrointestinal Diseases epidemiology, Hospitalization statistics & numerical data, Humans, Infant, Intensive Care, Neonatal statistics & numerical data, London epidemiology, Male, Milk, Human, Cytomegalovirus Infections complications, Gastrointestinal Diseases virology
- Abstract
Sixteen cases of postnatal cytomegalovirus (CMV) infection were identified in a neonatal intensive care unit population over a five year period. Eleven of these infants had gastrointestinal signs at the time of presentation. These ranged from minor and transient (abdominal distension and enteral feed intolerance) to severe and life threatening (protein losing enteropathy, diarrhoea, and hypernatraemic dehydration). An initial diagnosis of necrotising enterocolitis was common, but no infant showed intestinal or hepatic portal pneumatosis. The gestational age of the infants was 24-38 weeks. All had received fresh maternal breast milk. It is suggested that CMV enteritis is added to the spectrum of clinical manifestations of postnatal CMV infection. Signs suggestive of necrotising enterocolitis with atypical features should prompt investigations for CMV infection.
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- 2004
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154. Seroepidemiological study of herpes simplex virus types 1 and 2 in Brazil, Estonia, India, Morocco, and Sri Lanka.
- Author
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Cowan FM, French RS, Mayaud P, Gopal R, Robinson NJ, de Oliveira SA, Faillace T, Uusküla A, Nygård-Kibur M, Ramalingam S, Sridharan G, El Aouad R, Alami K, Rbai M, Sunil-Chandra NP, and Brown DW
- Subjects
- Adolescent, Adult, Brazil epidemiology, Child, Child, Preschool, Estonia epidemiology, Female, Herpesvirus 1, Human immunology, Herpesvirus 2, Human immunology, Humans, India epidemiology, Infant, Infant, Newborn, Male, Morocco epidemiology, Odds Ratio, Prevalence, Seroepidemiologic Studies, Sri Lanka epidemiology, Herpes Simplex epidemiology
- Abstract
Background: The association between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus (HIV) and the development of HSV vaccines have increased interest in the study of HSV epidemiology., Objectives: To estimate the age and sex specific seroprevalence of HSV-1 and HSV-2 infections in selected populations in Brazil, Estonia, India, Morocco, and Sri Lanka., Methods: Serum samples were collected from various populations including children, antenatal clinic attenders, blood donors, hospital inpatients, and HIV sentinel surveillance groups. STD clinic attenders were enrolled in Sri Lanka, male military personnel in Morocco. Sera were tested using a common algorithm by type specific HSV-1 and HSV-2 antibody assay., Results: 13,986 samples were tested, 45.0% from adult females, 32.7% from adult males, and 22.3% from children. The prevalence of HSV-1 varied by site ranging from 78.5%-93.6% in adult males and from 75.5%-97.8% in adult females. In all countries HSV-1 seroprevalence increased significantly with age (p<0.001) in both men and women. The prevalence of HSV-2 infection varied between sites. Brazil had the highest age specific rates of infection for both men and women, followed by Sri Lanka for men and Estonia for women, the lowest rates being found in Estonia for men and India for women. In all countries, HSV-2 seroprevalence increased significantly with age (p<0.01) and adult females had higher rates of infection than adult males by age of infection., Conclusions: HSV-1 and HSV-2 seroprevalence was consistently higher in women than men, particularly for HSV-2. Population based data on HSV-1 and HSV-2 will be useful for designing potential HSV-2 vaccination strategies and for focusing prevention efforts for HSV-1 and HSV-2 infection.
- Published
- 2003
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155. Magnetic resonance imaging of preterm brain injury.
- Author
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Counsell SJ, Rutherford MA, Cowan FM, and Edwards AD
- Subjects
- Cerebral Infarction diagnosis, Humans, Infant, Newborn, Infant, Premature, Intracranial Hemorrhages diagnosis, Brain Injuries diagnosis, Infant, Premature, Diseases diagnosis, Magnetic Resonance Imaging methods
- Abstract
Magnetic resonance imaging (MRI) has proved to be a valuable tool for monitoring development and pathology in the preterm brain. This imaging modality is useful for assessing numerous pathologies including periventricular leukomalacia, intraventricular haemorrhage/germinal layer haemorrhage, and periventricular haemorrhagic infarction, and can help to predict outcome in these infants. MRI has also allowed the detection of posterior fossa lesions, which are not easily seen with ultrasound. Additionally, and perhaps most relevant, quantitative MR studies have shown differences between the normal appearing preterm brain at term equivalent age and term born infants, confirming that the brain develops differently in the ex utero environment. Further studies using quantifiable MR techniques will improve our understanding of the effects of the ex utero environment, including aspects of neonatal intensive care on the developing brain.
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- 2003
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156. Improving young people's access to reproductive health care in rural Zimbabwe.
- Author
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Langhaug LF, Cowan FM, Nyamurera T, and Power R
- Subjects
- Adolescent, Adult, Attitude of Health Personnel, Contraception Behavior, Culture, Female, HIV Infections prevention & control, Health Services Needs and Demand, Humans, Male, Sexual Behavior, Sexually Transmitted Diseases prevention & control, Zimbabwe, Attitude to Health, Health Services Accessibility, Rural Health, Sex Education
- Abstract
The aim of this study was to explore ways to improve the accessibility of clinics for young people with reproductive health problems in rural Zimbabwe. This study, which took place in rural Masvingo, was part of a project to develop a comprehensive adolescent reproductive health intervention for Zimbabwean youth. Six focus group discussions were held with secondary school pupils aged 16-19; four focus group discussions were held with nurses. Additionally, 16 community meetings with parents of adolescents were observed. The data were analyzed using the principles of grounded theory: three main categories and several sub-categories emerged from the data. The accessibility of existing services for young people was poor, partly because nurses were reluctant to provide such services due to lack of clarity in legislation and also through fear of condoning adolescent sexual activity. Although the clinical acumen of staff was recognized as sound, service delivery was perceived to be judgemental and lacking in confidentiality and privacy. This reflects the cultural context in which services are delivered. Culturally, adolescents are deemed to be children and as such to have few rights. There is a widely held belief that teaching young people about sex will promote sexual activity. Our findings suggested that staff training should focus on attitudinal rather than medical issues.
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- 2003
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157. An evidence based approach to testing for antibody to herpes simplex virus type 2.
- Author
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Copas AJ, Cowan FM, Cunningham AL, and Mindel A
- Subjects
- Adult, Aged, Analysis of Variance, Blotting, Western, Cross-Sectional Studies, Enzyme-Linked Immunosorbent Assay methods, Female, Herpes Genitalis immunology, Herpes Genitalis virology, Humans, Male, Middle Aged, Predictive Value of Tests, Risk Assessment, Risk Factors, Sexual Partners, Antibodies, Viral analysis, Herpes Genitalis diagnosis, Herpesvirus 2, Human immunology
- Abstract
Objectives: To establish whether a simple risk scoring system, based on limited information, can reflect the variation in HSV-2 prevalence in a population, and whether a common system can be used across settings. To establish whether knowledge of a patient's score can aid the interpretation of the result from one of the commercial type specific assays., Methods: Four previous cross sectional studies are considered, with HSV-2 antibody results by western blot or type specific ELISA tests. The clinical settings were a blood donor centre (1359 participants) and STD clinic (808 participants), London, United Kingdom, an antenatal clinic, Sydney, Australia (2317 participants), and a family medical centre, Seattle, United States (478 participants). We determined the factors associated with HSV-2 prevalence, the similarity of associations across settings, and the variation in HSV-2 prevalence by risk score., Results: A simple scoring captured much variation in HSV-2 prevalence in each population-for example, for London blood donors, scoring based on sex, age, and number of lifetime partners, prevalence varied from 0.7% (95% CI 0.1 to 2.0) to 47.3% (37.9 to 56.6) across five risk groups. For number of lifetime partners, and sex, the association with HSV-2 varied significantly across studies., Conclusions: A scoring system can aid test interpretation-for example, in London blood donors the post-test probability of infection following a positive result varies from around 25% to 98% across risk groups for a typical type specific assay. Further work could address whether this theoretical benefit can be realised in practice. A common risk scoring probably could not be used across settings.
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- 2002
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158. Herpes simplex virus type 1 infection: a sexually transmitted infection of adolescence?
- Author
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Cowan FM, Copas A, Johnson AM, Ashley R, Corey L, and Mindel A
- Subjects
- Adolescent, Adult, Aged, Blotting, Western, Female, Humans, Male, Middle Aged, Sexual Behavior, Antibodies, Viral blood, Herpes Simplex immunology, Herpesvirus 1, Human immunology
- Abstract
Objectives: To examine the factors associated with antibodies to herpes simplex virus type 1 (HSV-1)., Design: Cross sectional study with HSV-1 antibody testing performed by University of Washington western blot assay., Setting: Central London STD clinic (1990-1) and central London blood donation centre (1992)., Participants: Representative sample of 869 new and rebooked GUM clinic attenders and 1494 consecutive blood donors., Results: The prevalence of HSV-1 antibody among clinic attenders was 60.4% (95% CI 57.0 to 63.7) and among donors was 46.1% (95% CI 43.5 to 48.7). HSV-1 antibody was independently associated with increasing age in both populations (p<0.001). Among clinic attenders, HSV-1 was less common among heterosexual men than women and homosexual men (p<0.005), and was more common among black people (p=0.001) and those of lower socioeconomic status (p=0.05). Among blood donors, being single rather than married was independently associated with HSV-1 infection (p=0.03). Early age at first intercourse was strongly associated with presence of HSV-1 in both populations. The adjusted odds of HSV-1 among GUM clinic attenders was 0.37 (95% CI 0.21 to 0.65) for someone aged 20 at first intercourse compared with someone aged
- Published
- 2002
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159. Adolescent reproductive health interventions.
- Author
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Cowan FM
- Subjects
- Adolescent, Adolescent Health Services organization & administration, Behavior Therapy methods, Delivery of Health Care organization & administration, HIV Infections prevention & control, Humans, Outcome Assessment, Health Care, Reproduction, Risk Factors, Sexually Transmitted Diseases prevention & control, Adolescent Behavior, Sexual Behavior
- Published
- 2002
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160. Suppression of sulfur mustard-increased IL-8 in human keratinocyte cell cultures by serine protease inhibitors: implications for toxicity and medical countermeasures.
- Author
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Cowan FM, Broomfield CA, and Smith WJ
- Subjects
- Animal Testing Alternatives, Cells, Cultured, Humans, Interleukin-8 biosynthesis, Keratinocytes drug effects, Tosyllysine Chloromethyl Ketone pharmacology, Chemical Warfare Agents toxicity, Interleukin-8 antagonists & inhibitors, Keratinocytes metabolism, Mustard Gas toxicity, Serine Proteinase Inhibitors pharmacology
- Abstract
The toxicity of the chemical warfare blistering agent sulfur mustard (2,2'-dichlorodiethyl sulfide; SM) has been investigated for nearly a century; however, the toxicological mechanisms of SM remain obscure and no antidote exists. The similarity of dermal-epidermal separation caused by SM exposure, proteolysis, and certain bullous diseases has fostered the hypothesis that SM vesication involves proteolysis and/or inflammation. Compound screening conducted by the US Army Medical Research Institute of Chemical Defense established that topical application of three tested serine protease inhibitors could reduce SM toxicity in the mouse ear vesicant model. Although most of the drugs with efficacy for SM toxicity in rodent models are anti-inflammatory compounds, no in vitro assay is in current use for screening of potential anti-inflammatory SM antidotes. IL-8 is a potent neutrophil chemotactic cytokine that is increased in human epidermal keratinocyte (HEK) cell cultures following exposure to SM and has been proposed as a marker for SM-induced inflammation. This study was conducted to establish in vitro screening of IL-8 in SM-exposed HEK as a possible model for evaluating candidate compounds prior to in vivo testing. We chose two protease inhibitors, one from those shown as successful in the MEVM (ethyl p-guanidinobenzoate hydrochloride, ICD 1579) and a prototypic inhibitor of trypsin, N-tosyl-L-lysine chloromethyl ketone (TLCK). TLCK (62.5 to 1000 micromol/L) or ICD 1579 (31.25 to 1000 micromol/L) was added to HEK cell cultures 1 h after SM exposure (200 micromol/L) and dose-dependently suppressed SM-increased IL-8. The suppression of SM-increased IL-8 by a class of drug candidate compounds such as protease inhibitors may provide a mechanistic marker that helps predict future medical countermeasures for SM toxicity and reduces the need for testing in animal models.
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- 2002
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161. Early increases in brain myo-inositol measured by proton magnetic resonance spectroscopy in term infants with neonatal encephalopathy.
- Author
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Robertson NJ, Lewis RH, Cowan FM, Allsop JM, Counsell SJ, Edwards AD, and Cox IJ
- Subjects
- Apgar Score, Brain pathology, Brain Diseases, Metabolic pathology, Brain Diseases, Metabolic therapy, Creatinine metabolism, Gestational Age, Humans, Infant, Newborn, Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy methods, Treatment Outcome, Brain metabolism, Brain Diseases, Metabolic metabolism, Inositol metabolism
- Abstract
Our aim was to assess brain myo-inositol/creatine plus phosphocreatine (Cr) in the first week in term infants with neonatal encephalopathy using localized short echo time proton magnetic resonance spectroscopy and to relate this to measures of brain injury, specifically lactate/Cr in the first week, basal ganglia changes on magnetic resonance imaging (MRI), and neurodevelopmental outcome at 1 y. Fourteen term infants with neonatal encephalopathy of gestational age (mean +/- SD) 39.6 +/- 1.6 wk, birth weight 3270 +/- 490 g, underwent MRI and magnetic resonance spectroscopy at 3.5 +/- 2.1 d. Five infants were entered in a pilot study of treatment with moderate whole-body hypothermia for neonatal encephalopathy; two were being cooled at the time of the scan. T(1)- and T(2)-weighted transverse magnetic resonance images were graded as normal or abnormal according to the presence or absence of the normal signal intensity of the posterior limb of the internal capsule and signal intensity changes in the basal ganglia. Localized proton magnetic resonance spectroscopy data were obtained from an 8-cm(3) voxel in the basal ganglia using echo times of 40 and 270 ms, and the peak area ratios of myo-inositol/Cr and lactate/Cr were measured. Outcome was scored using Griffith's development scales and neurodevelopmental examination at 1 y. MRI and outcome were normal in six infants and abnormal in eight. myo-Inositol/Cr and lactate/Cr were higher in infants with abnormal MRI and outcome (p < 0.01, p < 0.01, respectively). myo-Inositol/Cr and lactate/Cr were correlated (p < 0.01) and were both correlated to the Griffith's developmental scales (p < 0.01, p < 0.01, respectively). In conclusion, these preliminary data suggest that early increases in brain basal ganglia myo-inositol/Cr in infants with neonatal encephalopathy are associated with increased lactate/Cr, MRI changes of severe injury, and a poor neurodevelopmental outcome at 1 y.
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- 2001
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162. European guideline for the management of genital herpes.
- Author
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Patel R, Barton SE, Brown D, Cowan FM, Kinghorn GR, Munday PE, Scoular A, Timmins D, Whittaker M, and Woolley P
- Subjects
- Antiviral Agents therapeutic use, Europe, Female, Herpes Genitalis diagnosis, Herpes Genitalis drug therapy, Humans, Infant, Newborn, Pregnancy, Pregnancy Complications, Infectious diagnosis, Pregnancy Complications, Infectious drug therapy, Simplexvirus isolation & purification, Herpes Genitalis prevention & control, Pregnancy Complications, Infectious prevention & control
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- 2001
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163. Protective action of the serine protease inhibitor N-tosyl-L-lysine chloromethyl ketone (TLCK) against acute soman poisoning.
- Author
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Cowan FM, Broomfield CA, Lenz DE, and Shih TM
- Subjects
- Animals, Atropine administration & dosage, Chemical Warfare Agents poisoning, Drug Interactions, Guinea Pigs, Injections, Intramuscular, Injections, Intraperitoneal, Injections, Subcutaneous, Lethal Dose 50, Male, Reflex drug effects, Seizures chemically induced, Seizures prevention & control, Soman administration & dosage, Soman poisoning, Soman toxicity, Time Factors, Tosyllysine Chloromethyl Ketone administration & dosage, Atropine therapeutic use, Cholinesterase Inhibitors poisoning, Serine Proteinase Inhibitors pharmacology, Soman antagonists & inhibitors, Tosyllysine Chloromethyl Ketone pharmacology
- Abstract
Soman-poisoned rats display cholinergic crisis, a systemic mast cell degranulation characteristic of anaphylactic reactions and an excitotoxin-like sequential seizure and neuronal degeneration. The protection of guinea pigs from soman lethality by prophylactic administration of the serine protease inhibitor suramin suggests a possible proteolytic component in soman poisoning. The present study tested the effect of N-tosyl-L-lysine chloromethyl ketone (TLCK), an inhibitor of trypsin-like serine proteases, on soman-induced toxic signs (convulsions, righting reflex) and survival time. Nine control guinea pigs receiving 2 x LD(50) (56 microg kg(-1), s.c.) of soman immediately followed by a therapeutic dose of atropine sulfate (17.4 mg kg(-1) i.m.) experienced severe convulsions, and 8/9 lost the righting reflex. Six of these nine animals expired within 65 min; the three remaining animals survived 24 h to termination of the experiment. When a second group of animals were given TLCK (12 mg kg(-1), i.p.) 30 min prior to a 2 x LD(50) soman challenge and atropine-sulfate therapy, 5/9 experienced convulsions and only 3/9 lost the righting reflex. All nine animals survived beyond 4 h, with six surviving to 24 h. Compared with soman controls, prophylaxis with TLCK significantly prevented the loss of righting reflex (P = 0.05) and enhanced 4-h survival (P = 0.005). Although, convulsions were reduced and 24-h survival was improved in TLCK-treated animals, these results were not statistically significant. The protection from soman toxicity by chemically distinct protease inhibitors such as suramin and TLCK suggests a role for pathological proteolytic pathways in soman intoxication., (Copyright 2001 John Wiley & Sons, Ltd.)
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- 2001
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164. A cognitive behavioural intervention to reduce sexually transmitted infections among gay men: randomised trial.
- Author
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Imrie J, Stephenson JM, Cowan FM, Wanigaratne S, Billington AJ, Copas AJ, French L, French PD, and Johnson AM
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- Adolescent, Adult, Humans, Male, Middle Aged, Self Disclosure, Treatment Failure, Cognitive Behavioral Therapy, Homosexuality, Risk-Taking, Sexually Transmitted Diseases prevention & control
- Abstract
Objective: To determine the effectiveness of a brief cognitive behavioural intervention in reducing the incidence of sexually transmitted infections among gay men., Design: Randomised controlled trial with 12 months' follow up., Setting: Sexual health clinic in London., Participants: 343 gay men with an acute sexually transmitted infection or who reported having had unprotected anal intercourse in the past year., Main Outcome Measures: Number of new sexually transmitted infections diagnosed during follow up and self reported incidence of unprotected anal intercourse., Results: 72% (361/499) of men invited to enter the study did so. 90% (308/343) of participants returned at least one follow up questionnaire or re-attended the clinic and requested a check up for sexually transmitted infections during follow up. At baseline, 37% (63/172) of the intervention group and 30% (50/166) of the control group reported having had unprotected anal intercourse in the past month. At 12 months, the proportions were 27% (31/114) and 32% ( 39/124) respectively (P=0.56). However, 31% (38/123) of the intervention group and 21% (35/168) of controls had had at least one new infection diagnosed at the clinic (adjusted odds ratio 1.66, 95% confidence interval 1.00 to 2.74). Considering only men who requested a check up for sexually transmitted infections, the proportion diagnosed with a new infection was 58% (53/91) for men in the intervention group and 43% (35/81) for men in the control group (adjusted odds ratio 1.84, 0.99 to 3.40). Using a regional database that includes information from 23 sexual health clinics in London, we determined that few participants had attended other sexual health clinics., Conclusions: This behavioural intervention was acceptable and feasible to deliver, but it did not reduce the risk of acquiring a new sexually transmitted infection among these gay men at high risk. Even carefully designed interventions should not be assumed to bring benefit. It is important to evaluate their effects in randomised trials with objective clinical end points.
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- 2001
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165. Diffusion-weighted imaging in neonates.
- Author
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Bydder GM, Rutherford MA, and Cowan FM
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- Brain pathology, Brain Damage, Chronic diagnosis, Diffusion, Humans, Infant, Newborn, Prognosis, Sensitivity and Specificity, Cerebral Infarction diagnosis, Hypoxia-Ischemia, Brain diagnosis, Image Enhancement, Magnetic Resonance Imaging
- Abstract
Diffusion-weighted imaging (DWI) can readily be performed in the neonate, although currently studies remain a few years behind-those carried out on adults. DWI relies on the random diffusion of water molecules. As for the adult population, a pulsed gradient spin echo sequence (PGSE) with cardiac gating can be used to exploit the effect of diffusion on image contrast and to determine the apparent diffusion coefficient (D*) for tissues or fluids. Anisotropic properties caused by the restriction of the movement of water molecules may be demonstrated. In the neonatal brain restricted motion can be detected in both myelinated and unmyelinated white matter tracts. DWI has been used to study changes in global and focal ischaemic injury to the neonatal brain. A decreased D* may be documented after an ischaemic insult followed by a gradual increase. These changes are consistent with animal data but show a slower time course. Intervention following perinatal ischaemic injury must be started within hours. DWI detects early ischaemic injury and may therefore be a useful tool for identifying those infants who could benefit from intervention.
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- 2001
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166. Intrauterine rescue transfusion in monochorionic multiple pregnancies with recent single intrauterine death.
- Author
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Tanawattanacharoen S, Taylor MJ, Letsky EA, Cox PM, Cowan FM, and Fisk NM
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- Acidosis diagnosis, Anemia diagnosis, Anemia therapy, Brain Diseases diagnostic imaging, Female, Fetal Diseases therapy, Gestational Age, Humans, Pregnancy, Prenatal Diagnosis, Triplets, Twins, Ultrasonography, Prenatal, Blood Transfusion, Intrauterine, Diseases in Twins, Fetal Death, Pregnancy, Multiple
- Abstract
To assess the role of fetal blood sampling and intrauterine transfusion in monochorionic (MC) multiple pregnancy complicated by single intrauterine death (IUD), we reviewed ten cases over a 4-year period in a tertiary referral centre which underwent fetal blood sampling within 24 h of death of its MC co-twin. Intrauterine rescue transfusion was performed in all seven anaemic fetuses (hematocrit; Hct < 30%) to raise the fetal Hct to > or = 40%. The rationale was to prevent death and/or brain injury. Two fetuses, which were severely acidaemic at blood sampling, died in utero within 24 h of the procedure. In two cases, the surviving twins manifested abnormal sonographic findings of the fetal brain 2-5 weeks later and underwent late termination. In two cases, the pregnancies continued uneventfully until delivery at 35 and 40 weeks' gestation with good neonatal outcome. In one case the co-twin delivered 1 week later at 29 weeks but died within 12 h. Fetuses without anaemia were not transfused and had normal clinical outcomes. We suggest that intrauterine rescue transfusion before the development of severe acidaemia in anaemic surviving MC co-twins may prevent fetal death, but does not necessarily prevent brain injury. Until its role becomes clearer, we recommend that its use be restricted to situations in which the parents and the local jurisdiction allow late termination as an option if brain injury subsequently manifests on ultrasound., (Copyright 2001 John Wiley & Sons, Ltd.)
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- 2001
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167. Neonatal cranial ultrasound interpretation: a clinical audit.
- Author
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Reynolds PR, Dale RC, and Cowan FM
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- Education, Medical, Continuing methods, Humans, Infant, Newborn, Medical Audit, Medical Staff, Hospital classification, Medical Staff, Hospital education, Ultrasonography, Brain Diseases diagnostic imaging, Clinical Competence standards
- Abstract
Objective: To assess the abilities of doctors to interpret neonatal cranial ultrasound scans., Design and Setting: High resolution scanned images of six important neonatal cranial ultrasound abnormalities were posted as a questionnaire to the 59 neonatal units in the North and South Thames regions., Results: Forty two questionnaires were returned (71%). Currently 56% of those interpreting cranial ultrasound scans are neonatal registrars, 27% are consultant paediatricians or neonatologists, and 17% are radiologists. The response rate from registrars was excellent (97%), but it was poor from consultant paediatric (38%) and radiological (40%) staff. The mean accurate identification of cerebral abnormalities was only 59% (range 45-71%). Only 44% of the neonatal registrars, compared with nearly all the consultant staff, have had any formal training in cranial ultrasonography., Conclusions: The data highlight the current accuracy of neonatal cranial ultrasound scan reporting in the Greater London region and have important implications for clinical services and research studies. Doctors who are responsible for interpreting neonatal cranial ultrasound scans should have formal training and supervision, and more formal reporting would improve and maintain standards. The findings raise significant doubts about the accuracy of local interpretation of cranial ultrasound scans in multicentre research studies.
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- 2001
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168. Exposure of human epidermal keratinocyte cell cultures to sulfur mustard promotes binding of complement C1q: implications for toxicity and medical countermeasures.
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Cowan FM, Broomfield CA, and Smith WJ
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- Antigens, Surface, Apoptosis, Binding Sites, Blister chemically induced, Blister physiopathology, Carrier Proteins, Cell Culture Techniques, Humans, Inflammation, Keratinocytes physiology, Mitochondrial Proteins, Complement C1q metabolism, Dermatologic Agents toxicity, Hyaluronan Receptors, Keratinocytes drug effects, Membrane Glycoproteins, Mustard Gas toxicity, Receptors, Complement physiology, Receptors, Fc biosynthesis
- Abstract
Sulfur mustard (HD)-increased proteolytic activity, HD-enhanced expression of Fc receptor (FcR) on human epidermal keratinocytes (HEK) and associated inflammatory responses may contribute to HD pathology. Like the FcR, the first component of the classical complement (C') cascade, C1q, binds to the Fc region of antibody to mediate inflammatory responses. Complement C1q binds specifically to the C1q receptor (C1qR) on the blebs of apoptotic human keratinocytes and is proposed as a cell surface marker for apoptosis. Assays by fluorescent antibodies demonstrated significantly enhanced binding of C1q to HEK cell cultures exposed to HD. The cell populations of HEK that showed enhanced C1q binding also demonstrated an intermediate uptake of propidium iodide that was greater than in viable unexposed cells but less than in dead cells. The HD-enhanced C1q binding was concentration-dependent, negative by flow cytometry or weakly positive by digital scanning microscopy at 100 microM and positive by both methods at 300 microM. Binding of C1q was also time-dependent, weakly positive at 8 h, and positive at 16 and 24 h after HD exposure. The HD-increased C1qR that binds C1q to the surface of HEK might be a contributing mechanism or a marker for the inflammation and vesication associated with HD exposure.
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- 2000
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169. Pilot study of treatment with whole body hypothermia for neonatal encephalopathy.
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Azzopardi D, Robertson NJ, Cowan FM, Rutherford MA, Rampling M, and Edwards AD
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- Asphyxia Neonatorum blood, Asphyxia Neonatorum complications, Asphyxia Neonatorum physiopathology, Blood Viscosity, Body Temperature, Brain Diseases etiology, Electroencephalography, Hemodynamics, Humans, Infant, Newborn, Pilot Projects, Treatment Outcome, Asphyxia Neonatorum therapy, Brain Diseases prevention & control, Hypothermia, Induced adverse effects
- Abstract
Background: There is extensive experimental evidence to support the investigation of treatment with mild hypothermia after birth asphyxia. However, clinical studies have been delayed by the difficulty in predicting long-term outcome very soon after birth and by concern about adverse effects of hypothermia., Objectives: The objectives of this study were to determine whether it is feasible to select infants with a bad neurological prognosis and to begin hypothermic therapy within 6 hours of birth, and to observe the effect of this therapy on relevant physiologic variables., Methods: Sixteen newborn infants with clinical features of birth asphyxia (median cord blood pH: 6.74; range: 6.58-7.08) were assessed by amplitude integrated electroencephalography (aEEG), and mild whole body hypothermia was instituted within 6 hours of birth in the 10 infants with an aEEG prognostic of a bad outcome. Rectal temperature was maintained at 33.2 +/- (standard deviation).6 degrees C for 48 hours. Rectal and tympanic membrane temperature, blood pressure, heart rate, blood gases, blood lactate, full blood count, blood electrolytes, high and low shear rate viscosity, and coagulation studies were monitored during and after cooling. A preliminary assessment of neurological outcome was made by repeated magnetic resonance imaging (MRI) and neurological examination., Results: All infants selected to receive hypothermia developed convulsions and a severe encephalopathy. During 48 hours of hypothermia infants had prolonged metabolic acidosis (median pH: 7.30; base excess: -6.3 mmol x L(-1), a high blood lactate (median lactate: 5.3 mmol x L(-1)) and low blood potassium levels (median value: 3.9 mmol x L(-1)) x Hypothermia was associated with lower heart rate and higher mean blood pressure. However, these changes did not seem to be clinically relevant and no significant complication of hypothermia was encountered. Blood viscosity and coagulation studies were similar during and after cooling. Unusual MRI findings were noted in 3 infants: transverse sinus thrombosis with subsequent small cerebellar infarct; probable thrombosis in the straight sinus; and hemorrhagic cerebral infarction. Six of the 10 cooled infants had minor abnormalities only or normal follow-up neurological examination; 3 infants died and 1 had major abnormalities. None of the 6 infants with a normal aEEG developed severe neonatal encephalopathy or neurological sequel., Conclusions: After birth asphyxia infants can be objectively selected by aEEG and hypothermia started within 6 hours of birth in infants at high risk of developing severe neonatal encephalopathy. Prolonged mild hypothermia to 33 degrees C to 34 degrees C is associated with minor physiologic abnormalities. Further studies of both the safety and efficacy of mild hypothermia, including further neuroimaging studies, are warranted.
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- 2000
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170. Levonorgestrel-releasing (20 microgram/day) intrauterine systems (Mirena) compared with other methods of reversible contraceptives.
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French RS, Cowan FM, Mansour D, Higgins JP, Robinson A, Procter T, Morris S, and Guillebaud J
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- Contraceptive Agents, Female adverse effects, Counseling, Female, Humans, Levonorgestrel adverse effects, Menstruation Disturbances chemically induced, Meta-Analysis as Topic, Randomized Controlled Trials as Topic, Risk Factors, Contraception methods, Contraceptive Agents, Female administration & dosage, Intrauterine Devices, Medicated, Levonorgestrel administration & dosage
- Abstract
Objective: To assess the relative contraceptive effectiveness, tolerability and acceptability of the levonorgestrel-releasing (20 microg per day) intrauterine system (LNG-20) compared with reversible contraceptive methods in women of reproductive age., Design: A systematic review and meta-analysis of randomised controlled trials., Identification: Studies were identified through seven databases, and by contacting investigators and organisations working in the contraceptive field., Main Outcome Measures: Unplanned pregnancy and continuation of contraceptive method., Results: Five of the seven randomised controlled trials which met the inclusion criteria were included in the meta-analyses; four were comparisons of the LNG-20 intrauterine system with nonhormonal intrauterine devices. LNG-20 intrauterine systems were compared with intrauterine devices divided into two categories, those > 250 mm3 (Copper T 380 Ag and Copper T 380A intrauterine devices) and those < or = 250 mm3 (Nova-T, Copper T 220C and Copper 200 intrauterine devices). Pregnancy rates for the LNG-20 intrauterine system users were significantly less likely to become pregnant compared with users of intrauterine devices < or = 250 mm3, and significantly less likely to have an ectopic pregnancy. LNG-20 intrauterine system users were more likely to experience amenorrhoea and device expulsion than women using intrauterine devices > 250 mm3. LNG-20 intrauterine system users were significantly more likely than all the intrauterine device users to discontinue because of hormonal side effects and amenorrhoea. When the LNG-20 intrauterine system was compared with Norplant-2, the LNG-20 users were significantly more likely to experience oligo-amenorrhoea, but significantly less likely to experience prolonged bleeding and spotting., Conclusions: The effectiveness of the LNG-20 intrauterine system was similar to or better than other contraceptive methods with which it was compared. Amenorrhoea was the main reason for the discontinuation of the LNG-20 intrauterine system, usually unnecessarily, since this end-organ suppression of bleeding is benign, associated with normal oestrogen levels. Women choosing this method should be informed of potential amenorrhoea when having pre-contraceptive counselling and that absent bleeding may be viewed as a positive outcome.
- Published
- 2000
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171. Reduced development of cerebral cortex in extremely preterm infants.
- Author
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Ajayi-Obe M, Saeed N, Cowan FM, Rutherford MA, and Edwards AD
- Subjects
- Gestational Age, Humans, Infant, Newborn, Infant, Premature, Magnetic Resonance Imaging, Cerebral Cortex growth & development, Infant, Very Low Birth Weight
- Abstract
Most growth in cortical connections and complexity occurs after 25 weeks. The cerebral cortex of extremely preterm infants when imaged at gestational age 38-42 weeks had less cortical surface area and was less complex than in normal infants born around term (p<0.0148 and p<0.0002, respectively), despite similar term-corrected cerebral tissue volumes. Since deficits acquired during critical periods of brain development may be permanent, these results suggest a neural substrate for the neurocognitive impairment that is frequent among such preterm infants.
- Published
- 2000
- Full Text
- View/download PDF
172. Head growth in infants with hypoxic-ischemic encephalopathy: correlation with neonatal magnetic resonance imaging.
- Author
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Mercuri E, Ricci D, Cowan FM, Lessing D, Frisone MF, Haataja L, Counsell SJ, Dubowitz LM, and Rutherford MA
- Subjects
- Apgar Score, Asphyxia Neonatorum diagnosis, Brain pathology, Cephalometry, Female, Fetal Distress diagnosis, Follow-Up Studies, Head growth & development, Humans, Infant, Infant, Newborn, Male, Neurologic Examination, Risk Factors, Brain Damage, Chronic diagnosis, Hypoxia-Ischemia, Brain diagnosis, Magnetic Resonance Imaging, Microcephaly diagnosis
- Abstract
Objectives: The aims of the study were to establish the relationship between head growth in the first year of life with the pattern on injury on neonatal magnetic resonance imaging (MRI) in infants with hypoxic-ischemic encephalopathy (HIE) and to relate these to the neurodevelopmental outcome., Methods: Fifty-two term infants who presented at birth with a neonatal encephalopathy consistent with HIE and who had neonatal brain MRI were entered into the study. Head circumference charts were evaluated retrospectively and the head growth over the first year of life compared with the pattern of brain lesions on MRI and with the neurodevelopmental outcome at 1 year of age. Suboptimal head growth was classified as a drop of >2 standard deviations across the percentiles with or without the development of microcephaly, which was classified as a head circumference below the third percentile., Results: There was no statistical difference between the neonatal head circumferences of the infants presenting with HIE and control infants. At 12 months, microcephaly was present in 48% of the infants with HIE, compared with 3% of the controls. Suboptimal head growth was documented in 53% of the infants with HIE, compared with 3% of the controls. Suboptimal head growth was significantly associated with the pattern of brain lesions, in particular to involvement of severe white matter and to severe basal ganglia and thalamic lesions. Suboptimal head growth predicted abnormal neurodevelopmental outcome with a sensitivity of 79% and a specificity of 78%, compared with the presence of microcephaly at 1 year of age, which had a sensitivity of only 65% and a specificity of 73%. The exceptions were explained by infants with only moderate white matter abnormalities who had suboptimal head growth but normal outcome at 1 year of age and by infants with moderate basal ganglia and thalamic lesions only who had normal head growth but significant motor abnormality.
- Published
- 2000
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- View/download PDF
173. Implantable contraceptives (subdermal implants and hormonally impregnated intrauterine systems) versus other forms of reversible contraceptives: two systematic reviews to assess relative effectiveness, acceptability, tolerability and cost-effectiveness.
- Author
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French RS, Cowan FM, Mansour DJ, Morris S, Procter T, Hughes D, Robinson A, and Guillebaud J
- Subjects
- Contraceptive Agents, Female economics, Cost-Benefit Analysis, Female, Humans, Injections, Subcutaneous, Levonorgestrel economics, Patient Satisfaction, Pregnancy, Prospective Studies, Technology Assessment, Biomedical, Treatment Outcome, Contraceptive Agents, Female administration & dosage, Drug Implants economics, Intrauterine Devices, Medicated economics, Levonorgestrel administration & dosage
- Published
- 2000
174. Cerebral intracellular lactic alkalosis persisting months after neonatal encephalopathy measured by magnetic resonance spectroscopy.
- Author
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Robertson NJ, Cox IJ, Cowan FM, Counsell SJ, Azzopardi D, and Edwards AD
- Subjects
- Brain pathology, Brain Diseases congenital, Brain Diseases metabolism, Brain Diseases pathology, Cytoplasm metabolism, Fetal Hypoxia, Humans, Infant, Infant, Newborn, Lactic Acid analysis, Magnetic Resonance Spectroscopy, Oxidation-Reduction, Regression Analysis, Time Factors, Brain metabolism, Brain Diseases diagnosis, Lactic Acid metabolism
- Abstract
We have found that cerebral lactate can be detected later than 1 month of age after neonatal encephalopathy (NE) in infants with severe neurodevelopmental impairment at 1 y. Our hypothesis was that persisting lactate after NE is associated with alkalosis and a decreased cell phosphorylation potential. Forty-three infants with NE underwent proton and phosphorus-31 magnetic resonance spectroscopy at 0.2-56 wk postnatal age. Seventy-seven examinations were obtained: 25 aged <2 wk, 16 aged > or = 2 to < or = 4 wk, 25 aged > 4 to < or = 30 wk, and 11 aged > 30 wk. Neurodevelopmental outcome was assessed at 1 y of age: 17 infants had a normal outcome and 26 infants had an abnormal outcome. Using univariate linear regression, we determined that increased lactate/creatine plus phosphocreatine (Cr) was associated with an alkaline intracellular pH (pHi) (p < 0.001) and increased inorganic phosphate/phosphocreatine (Pi/PCr) (p < 0.001). This relationship was significant, irrespective of outcome group or age at time of study. Between outcome groups, there were significant differences for lactate/Cr measured at < 2 wk (p = 0.005) and > 4 to < or = 30 wk (p = 0.01); Pi/PCr measured at < 2 wk (p < 0.001); pHi measured at < 2 wk (p < 0.001), > or = 2 to < or = 4 wk (p = 0.02) and > 4 to < or = 30 wk (p = 0.03); and for N-acetylaspartate/Cr measured at > or = 2 to < or = 4 wk (p = 0.03) and > 4 to < or = 30 wk (p = 0.01). Possible mechanisms leading to this persisting cerebral lactic alkalosis are a prolonged change in redox state within neuronal cells, the presence of phagocytic cells, the proliferation of glial cells, or altered buffering mechanisms. These findings may have implications for therapeutic intervention.
- Published
- 1999
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- View/download PDF
175. Reproducibility and accuracy of MR imaging of the brain after severe birth asphyxia.
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Jouvet P, Cowan FM, Cox P, Lazda E, Rutherford MA, Wigglesworth J, Mehmet H, and Edwards AD
- Subjects
- Asphyxia Neonatorum pathology, Humans, Infant, Newborn, Observer Variation, Predictive Value of Tests, Reproducibility of Results, Sensitivity and Specificity, Asphyxia Neonatorum diagnosis, Brain pathology, Magnetic Resonance Imaging
- Abstract
Background and Purpose: MR imaging of the brain can be used to detect cerebral damage after suspected hypoxic-ischemic injury. This study examines the reproducibility and accuracy of MR imaging soon after severe birth asphyxia., Methods: During a 48-month period, full-term newborn neonates, who died within the first week as a result of severe hypoxic ischemic encephalopathy, were included in the study if they had undergone early (<5 days old) MR imaging and postmortem neuropathologic studies. Two trained observers assessed reproducibility by examining multiple brain regions independently with current criteria and then defining and applying improved criteria. Accuracy of MR findings was tested by comparing the brain regions about which the two imaging raters agreed to those regions about which the two pathologists agreed., Results: Eight neonates, with a median gestational age of 40 weeks (range, 38-40 weeks) and who suffered severe birth asphyxia, were included in the study. In the reproducibility study, MR imaging agreement was moderate when current criteria were used (k = .44). Using the improved criteria, agreement increased considerably (k = .62). Much of this improvement was due to limiting the analyses to the posterior limb of the internal capsule, thalamus, parietal cortex, hippocampus, and medulla. The posterior limb of the internal capsule was the most reliable region analyzed. MR imaging agreement was similar to that achieved by two experienced pathologists reviewing the histologic sections (k = .66). In the accuracy study, MR imaging abnormality was predictive of pathologic abnormality with a sensitivity of .79 and a positive predictive value of 1.0. The predictive value of a single MR imaging abnormality was .79 (95% confidence interval, .61-.96)., Conclusion: Criteria that provide substantial reproducibility and accuracy for the interpretation of MR imaging findings very early after birth asphyxia can be derived.
- Published
- 1999
176. Imaging and laboratory investigation in herpes simplex encephalitis.
- Author
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Coren ME, Buchdahl RM, Cowan FM, Riches PG, Miles K, and Thompson EJ
- Subjects
- Antibodies, Viral cerebrospinal fluid, Brain pathology, Cerebrospinal Fluid virology, Electroencephalography, Encephalitis cerebrospinal fluid, Humans, Immunoelectrophoresis, Infant, Newborn, Magnetic Resonance Imaging, Male, Polymerase Chain Reaction, Simplexvirus immunology, Encephalitis diagnosis, Encephalitis virology, Herpes Simplex diagnosis
- Abstract
A 14 day old baby presented with signs of an acute encephalitis. Clinically, herpes simplex encephalitis (HSE) was suspected. Early MRI and EEG were normal and there was rapid clinical improvement. A negative polymerase chain reaction (PCR) result on the initial CSF sample seemed to make HSE most unlikely. This diagnosis was subsequently proved after demonstration of specific antibody production using immunoelectrophoresis of the CSF. The child had extensive damage to brain tissue. The need for sequential analysis of CSF in making or refuting this diagnosis is illustrated.
- Published
- 1999
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177. Assessment of neonatal encephalopathy by amplitude-integrated electroencephalography.
- Author
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al Naqeeb N, Edwards AD, Cowan FM, and Azzopardi D
- Subjects
- Asphyxia Neonatorum diagnosis, Asphyxia Neonatorum etiology, Brain Diseases complications, Brain Diseases epidemiology, Electroencephalography, Female, Follow-Up Studies, Gestational Age, Humans, Infant, Newborn, Magnetic Resonance Imaging, Male, Neurologic Examination, Observer Variation, Predictive Value of Tests, Brain Diseases diagnosis
- Abstract
Objective: To define normal and abnormal patterns, test interobserver variability, and the prognostic accuracy of amplitude-integrated electroencephalography (aEEG) soon after the onset of neonatal encephalopathy., Methods: Consecutive cases of neonatal encephalopathy (n = 56; gestation median, 40; range, 35-42 weeks) and healthy infants (n = 14; gestation median, 40; range, 39-40 weeks) were studied. aEEG was recorded using a cerebral function monitor, at median, 0, range, 0-21 days of age. Of the infants, 24 of the 56 with encephalopathy and all of the normal infants were studied within 12 hours of birth (median, 5; range, 3-12 hours). Forty infants were suspected of having suffered birth asphyxia. Criteria for normal and abnormal patterns were defined and the interobserver variability of these classifications determined. Results were compared with neurodevelopmental outcome assessed at 18 to 24 months of age. aEEG also was compared with a standard EEG and with magnetic resonance imaging., Results: The median upper margin of the widest band of aEEG activity in the control infants was 37.5 microV (range, 30-48 microV), and median lower margin was 8 microV (range, 6.5-11 microV). We classified the aEEG background activity as normal amplitude, the upper margin of band of aEEG activity >10 microV and the lower margin >5 microV; moderately abnormal amplitude, the upper margin of band of aEEG activity >10 microV and the lower margin =5 microV; and suppressed amplitude, the upper margin of the band of aEEG activity <10 microV and lower margin <5 microV. Recordings were analyzed further for the presence of seizures, defined as periods of sudden increase in voltage accompanied by a narrowing of the band of aEEG activity. Tests of interobserver variability showed excellent agreement both for assessment of amplitude (kappa statistic = 0.85) and for identification of seizures (kappa statistic = 0.76) There was a close relationship between the aEEG and subsequent outcome: 19 of 21 infants with a normal aEEG finding were normal on follow-up at 18 to 24 months of age, whereas 27 of 35 infants with a moderately abnormal or suppressed aEEG and/or seizures died or developed neurologic abnormalities. Thus, aEEG predicted outcome with a sensitivity of 0. 93, a specificity of 0.70, positive predictive value of 0.77, negative predictive value of 0.90, and the likelihood ratio of a positive result of 3.1 and a negative result of 0.06. For the 24 infants studied within 12 hours of birth, the corresponding results were sensitivity, 1.0; specificity, 0.82; positive predictive value, 0.85; negative predictive value, 1; likelihood ratio of a positive result, 5.5; and likelihood ratio of a negative result, 0.18., Conclusion: The aEEG is a simple but accurate and reproducible clinical tool that could be useful in the assessment of infants with encephalopathy.
- Published
- 1999
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178. Partner notification techniques.
- Author
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Fenton KA, Chippindale S, and Cowan FM
- Subjects
- Confidentiality, Correspondence as Topic, HIV Infections prevention & control, HIV Infections transmission, House Calls, Humans, Interviews as Topic, Patient Education as Topic, Referral and Consultation, Risk Factors, Sexually Transmitted Diseases prevention & control, Social Support, Telephone, Contact Tracing methods, Sexually Transmitted Diseases transmission
- Abstract
This article aimed to cover the range of techniques used in partner notification for sexually transmitted infections, including HIV. Many of the current methods were developed over the past 50 years, and very little operational research has since been undertaken to refine them. More work is needed to evaluate inexpensive strategies to improve patient referral, to determine the psychological and behavioral impact of partner notification and methods of incorporating social networks in partner notification programs.
- Published
- 1998
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179. Persistent increases in cerebral lactate concentration after birth asphyxia.
- Author
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Hanrahan JD, Cox IJ, Edwards AD, Cowan FM, Sargentoni J, Bell JD, Bryant DJ, Rutherford MA, and Azzopardi D
- Subjects
- Asphyxia Neonatorum physiopathology, Brain blood supply, Brain physiopathology, Humans, Infant, Newborn, Lactic Acid analysis, Magnetic Resonance Spectroscopy, Prospective Studies, Asphyxia Neonatorum metabolism, Brain metabolism, Lactic Acid metabolism
- Abstract
In this prospective study proton magnetic resonance spectroscopy (1H MRS) was used to test the hypothesis that lactate can be detected later than 1 mo after birth in the brains of infants who display severe neurodevelopmental impairment 1 y after transient perinatal hypoxia-ischemia. Data were obtained from three groups of infants: 1) eight infants suffering birth asphyxia followed by perinatal encephalopathy and abnormal neurodevelopmental outcome at 1 y of age (defined as major neurologic impairment, Griffiths quotient <85%, and low optimality score); 2) 10 infants with signs of perinatal hypoxia-ischemia but normal neurodevelopmental outcome at 1 y; and 3) six control infants with uneventful perinatal courses and normal neurodevelopment at 1 y. Between one and four examinations (median 1) were performed at median (range) 11 (4-68) wk after birth, and the cerebral concentration ratio of lactate to creatine plus phosphocreatine (Cr) calculated from each spectrum. Lactate was detected later than the 1st mo after birth in seven of eight infants with abnormal neurodevelopmental outcome [maximum detected lactate/Cr was median (range) 0.44 (0.24-0.67)]. No lactate was detected later than the 1st mo after birth in infants with normal neurodevelopmental outcome, nor in five of six control subjects, although a small amount of lactate was detected in one control infant (lactate/Cr=0.04). These results suggest that the pathologic postasphyxial process, indicated by persistent cerebral lactate, may not be confined to the period immediately after injury.
- Published
- 1998
- Full Text
- View/download PDF
180. Sulfur mustard exposure enhances Fc receptor expression on human epidermal keratinocytes in cell culture: implications for toxicity and medical countermeasures.
- Author
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Cowan FM, Broomfield CA, and Smith WJ
- Subjects
- Cells, Cultured, Epidermal Cells, Humans, Keratinocytes metabolism, Chemical Warfare Agents toxicity, Keratinocytes drug effects, Mustard Gas toxicity, Receptors, IgG biosynthesis
- Abstract
Sulfur mustard (HD) is a chemical warfare blister agent. The biochemical basis of HD-induced vesication is unknown, and no antidote currently exists. Basal epidermal cells are a major site of HD toxicity in vivo, with inflammation and HD-increased proteolytic activity implicated as factors that contribute to HD pathology. Fc receptors (FcR) bind to the Fc region of antibody to mediate many effector and regulatory functions that can influence inflammatory responses. FcR are found on all types of immune cells and are also expressed on the surface of human keratinocytes. Assay by fluorescent antibodies demonstrated significantly enhanced CD32 (FcRII) and CD16 (FcRIII) on human epidermal keratinocyte (HEK) cell cultures at 8 to 24 h after exposure to HD (50, 100 and 200 micromol/L). The enhanced CD32 was time- and concentration-dependent and agreed well with the time course of increased proteolysis and cutaneous pathology observed during HD vesication. HD-increased FcR on the surface of HEK might be a mechanism of vesication.
- Published
- 1998
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181. Abnormal magnetic resonance signal in the internal capsule predicts poor neurodevelopmental outcome in infants with hypoxic-ischemic encephalopathy.
- Author
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Rutherford MA, Pennock JM, Counsell SJ, Mercuri E, Cowan FM, Dubowitz LM, and Edwards AD
- Subjects
- Basal Ganglia pathology, Cerebral Cortex pathology, Dominance, Cerebral physiology, Female, Follow-Up Studies, Humans, Infant, Infant, Newborn, Male, Neurologic Examination, Sensitivity and Specificity, Thalamus pathology, Brain pathology, Brain Damage, Chronic diagnosis, Brain Ischemia diagnosis, Developmental Disabilities diagnosis, Hypoxia, Brain diagnosis, Magnetic Resonance Imaging
- Abstract
Objective: The aim of this study was to establish whether abnormal signal intensity in the posterior limb of the internal capsule (PLIC) on magnetic resonance imaging is an accurate predictor of neurodevelopmental outcome at 1 year of age in infants with hypoxic-ischemic encephalopathy (HIE)., Methods: We have examined 73 term neonates with HIE between 1 and 17 days after birth with cranial magnetic resonance imaging and related the magnetic resonance imaging findings to neurodevelopmental outcome at 1 year of age., Results: All infants with an abnormal signal intensity in the PLIC developed neurodevelopmental impairment although in 4 infants with very early scans the abnormal signal was not apparent until up to 4 days after birth. A normal signal intensity was associated with a normal outcome in all but 4 cases; 3 of these infants had minor impairments and all had persistent imaging changes within the white matter. The 4th infant with a normal signal intensity on day 2 died before a further image could be obtained. The absence of normal signal predicted abnormal outcome in term infants with HIE with a sensitivity of 0.90, a specificity of 1.0, a positive predictive value of 1.0, and a negative predictive value of 0.87. The test correctly predicted outcome in 93% of infants with grade II HIE, according to the Sarnat system. Applying a Bayesian approach, the predictive probability of the test (the probability that the test would predict an outcome correctly) was distributed with a mean of 0.94 and 95% confidence limits of 0.89 to 1.0., Conclusion: Abnormal signal intensity in the PLIC is an accurate predictor of neurodevelopmental outcome in term infants suffering HIE.
- Published
- 1998
- Full Text
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182. Guidelines for the management of herpes simplex virus infection in pregnancy.
- Author
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Cowan FM and Munday P
- Subjects
- Female, Humans, Pregnancy, Herpes Genitalis therapy, Practice Guidelines as Topic, Pregnancy Complications, Infectious therapy
- Published
- 1998
183. The management of herpes simplex virus infection in pregnancy.
- Author
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Smith JR, Cowan FM, and Munday P
- Subjects
- Female, Herpes Genitalis complications, Herpes Genitalis therapy, Herpes Simplex therapy, Herpesvirus 1, Human isolation & purification, Herpesvirus 2, Human isolation & purification, Humans, Infant, Newborn, Pregnancy, Pregnancy Complications, Infectious therapy, Pregnancy Trimester, Third, Prospective Studies, Recurrence, Herpes Simplex complications, Pregnancy Complications, Infectious microbiology
- Published
- 1998
- Full Text
- View/download PDF
184. Moving towards a Cochrane review group in sexually transmitted diseases.
- Author
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Cowan FM
- Subjects
- Humans, Randomized Controlled Trials as Topic, Review Literature as Topic, International Cooperation, Sexually Transmitted Diseases therapy
- Published
- 1998
185. Magnetic resonance imaging of the neonatal brain.
- Author
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Maalouf EF, Counsell S, Battin M, and Cowan FM
- Subjects
- Brain Ischemia diagnosis, Cerebral Infarction diagnosis, Humans, Infant, Newborn, Magnetic Resonance Imaging, Neonatal Screening, Brain abnormalities, Brain Injuries diagnosis, Central Nervous System Infections diagnosis
- Abstract
Advances in magnetic resonance technology have revolutionized our ability to obtain detailed images of the neonatal brain without the use of ionizing radiation. Magnetic resonance imaging has now become the modality of choice for the in-vivo assessment of brain development, myelination and pathology.
- Published
- 1998
186. Detection of subtle changes in the brains of infants and children via subvoxel registration and subtraction of serial MR images.
- Author
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Rutherford MA, Pennock JM, Cowan FM, Saeed N, Hajnal JV, and Bydder GM
- Subjects
- Brain anatomy & histology, Child, Child, Preschool, Diagnosis, Differential, Female, Humans, Infant, Infant, Newborn, Male, Observer Variation, Sensitivity and Specificity, Brain pathology, Brain Diseases diagnosis, Infant, Premature, Magnetic Resonance Imaging methods
- Abstract
Purpose: To compare conventional two-dimensional multisection images with registered three-dimensional volume and subtraction images for detecting subtle changes in the brains of infants and children., Methods: Twenty-six patients (24 with hemorrhagic/ischemic lesions) and one each with perinatal infection and Sturge-Weber disease were examined on two or more occasions with conventional multisection T1- and T2-weighted sequences as well as with 3-D T1-weighted volume sequences. A registration program was used to match the volume images to subvoxel dimensions, and subtracted images (second volume set minus the first) were obtained. The multisection images were compared with the 3-D and subtracted images and graded for detection of changes in a variety of brain structures., Results: In 16% to 33% of comparisons of different structures, the multisection images and the 3-D registered and subtracted images showed changes equally well. The 3-D registered and subtracted images were better than the multisection images in 67% to 84% of comparisons for detection of changes in the cerebral hemispheres, ventricles, brain stem, cerebellum, and in lesions. Statistically significant differences were found between the graded performance of the registered 3-D images and the conventional 2-D images in detecting cerebral infarction and hypoxic ischemic encephalopathy. In the late phase following neonatal cerebral infarction (1 to 11 months), the 3-D registered and subtracted images revealed growth of the brain at the margins of the lesions., Conclusion: Subvoxel registration of serial MR images may be of value in detecting subtle changes in the brains of infants and children.
- Published
- 1997
187. Does the brain regenerate after perinatal infarction?
- Author
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Rutherford MA, Pennock JM, Cowan FM, Dubowitz LM, Hajnal JV, and Bydder GM
- Subjects
- Brain pathology, Brain physiopathology, Cerebral Infarction diagnosis, Female, Follow-Up Studies, Humans, Infant, Infant, Newborn, Magnetic Resonance Imaging, Male, Neurologic Examination, Cerebral Infarction physiopathology, Nerve Regeneration physiology
- Abstract
We have used registered serial magnetic resonance scans to assess the growth of the brain after perinatal infarction in six infants. The initial scans were performed at ages of 4 days to 8 weeks and follow-up studies were performed from 4 days to 21 weeks later. A three-dimensional volume acquisition was performed on each occasion. Rigid body translations and rotations were used to match the images obtained on each occasion. Subtraction of the first image from the second then provided an assessment of the growth of the brain that had occurred between the two examinations. In the early phase of infarction (up to 2 months) low signal areas with clearly defined margins developed at the site of infarction. In the late phase (2 months onwards) growth was seen in the brain at the margins of the infarct in each case, and the size of the infarcted region showed a marked decrease in size. The rate of growth of the brain into the infarcted area exceeded that of the surrounding brain in some cases and was less in others. Growth of undamaged tissue may provide an important mechanism for recovery of the developing brain.
- Published
- 1997
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188. Chiari I malformation in asymptomatic young children with Williams syndrome: clinical and MRI study.
- Author
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Mercuri E, Atkinson J, Braddick O, Rutherford MA, Cowan FM, Counsell SJ, Dubowitz LM, and Bydder G
- Subjects
- Arnold-Chiari Malformation diagnosis, Brain pathology, Child, Preschool, Follow-Up Studies, Humans, Male, Williams Syndrome diagnosis, Arnold-Chiari Malformation genetics, Magnetic Resonance Imaging, Williams Syndrome genetics
- Abstract
We report clinical and magnetic resonance imaging findings in two young children, aged 2 years 4 months and 3 years, with Williams syndrome. Both showed a mild global delay, although their neurological examination was completely normal. Their magnetic resonance imaging, however, showed Chiari I malformation and some non-specific changes in the centrum semiovale and in the white matter posterior to the lateral ventricles. Cerebellar tonsils were displaced through the foramen magnum 8.5 and 7.5 mm respectively. Our results suggest that Chiari I malformation can also be a frequent feature in subjects with Williams syndrome even in the absence of overt neurological signs suggestive of it. Whether these children might develop acute signs later is not known at present. Further studies are needed not only to evaluate the incidence of these findings in the global population of subjects with Williams syndrome but also to identify the children who are at risk for developing acute neurological signs.
- Published
- 1997
- Full Text
- View/download PDF
189. Behavioural risk factors for HIV infection amongst blood donors in London.
- Author
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Cowan FM, Johnson AM, Wadsworth J, and Brennan M
- Subjects
- Adolescent, Adult, Aged, Female, Herpes Simplex epidemiology, Humans, London epidemiology, Male, Middle Aged, Prevalence, Proportional Hazards Models, Risk Factors, Sex Distribution, Surveys and Questionnaires, Acquired Immunodeficiency Syndrome epidemiology, Blood Donors psychology, HIV-1, Sexual Behavior
- Abstract
This paper compares the prevalence of risk factors for sexual acquisition of human immunodeficiency virus infection (HIV-1) among blood donors with the risk in the general population. Sexual behaviour data collected as part of a cross-sectional survey of central London blood donors were compared, after indirect standardization for age and sex, with those collected among Greater London participants of the National Survey of Sexual Attitudes and Lifestyles (NATSSAL). Overall, male blood donors had lower risk sexual lifestyles than age-matched NATSSAL participants in that they had had fewer lifetime female sexual partners, were more likely to have had first sexual intercourse after 16 years and were less likely to have had a homosexual partner. Men who have had sex with men since 1977 were asked not to donate blood. Despite this, 3.6% of male donors had had some sexual experience with another man and 1.9% had had sexual intercourse with at least one male partner. In contrast, female donors had had more sexual partners, were more likely to have had first sexual intercourse before 16 years and had probable higher rates of sexually transmitted disease (STD) clinic attendance than NATSSAL participants, explained by the much higher proportion of single rather than married female blood donors at each age. In conclusion, male donors had lower risk sexual lifestyles than age-matched NATSSAL participants, although even low levels of homosexual contact give some cause for concern. Female donors appeared to have higher risk sexual lifestyles than the general population because a much higher proportion of the female blood donors were single. The results provide important insights for those defining blood donor referral criteria.
- Published
- 1996
- Full Text
- View/download PDF
190. Monoclonal antibody blocking tests for the detection of HSV-1- and HSV-2-specific humoral responses: comparison with western blot assay.
- Author
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Slomka MJ, Ashley RL, Cowan FM, Cross A, and Brown DW
- Subjects
- Adolescent, Adult, Animals, Antibodies, Monoclonal immunology, Antibodies, Viral blood, Blotting, Western, Child, Child, Preschool, Chlorocebus aethiops, Herpes Genitalis blood, Herpes Genitalis virology, Herpes Simplex blood, Herpes Simplex immunology, Herpesvirus 1, Human isolation & purification, Herpesvirus 2, Human isolation & purification, Humans, Single-Blind Method, Vero Cells, Antibodies, Viral immunology, Herpes Genitalis immunology, Herpes Simplex virology, Herpesvirus 1, Human immunology, Herpesvirus 2, Human immunology, Radioimmunoassay methods
- Abstract
Monoclonal antibody blocking radioimmunoassays (MAb block RIAs) which detect specific humoral responses to each of the two human herpes simplex virus (HSV) types are described. RIAs were compared with Western blot assay (WBA) in a blind study of 64 sera obtained from clinically well-documented cases of genital herpes. WBA and MAb block RIA each detected HSV-1 antibodies in 16/17 (94%) sera from confirmed HSV-1 genital infections (first episodes and recurrent infections). Detection of HSV-2 antibody in 21 sera from HSV-2 first episodes was more effective by WBA which identified homologous antibody in 19 (96%), whereas MAb block RIA detected HSV-2 antibody in 16 (76%). HSV-2 antibody was detected in 24/25 (96%) sera from recurrent HSV-2 infections by WBA and by MAb block RIA, the highest degree of concordance for both methods. In addition, the MAb block RIA may be more effective in detecting the presence of HSV-1 antibody in sera from recurrent HSV-2 cases. Prevalence of HSV-1 and HSV-2 antibody was measured by the MAb block RIAs in 3 UK human study populations which consisted of 100 children/young adolescents, 104 adult blood donors and 80 genito-urinary medicine clinic attenders.
- Published
- 1995
- Full Text
- View/download PDF
191. Detection of propan-1,2-diol in neonatal brain by in vivo proton magnetic resonance spectroscopy.
- Author
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Cady EB, Lorek A, Penrice J, Reynolds EO, Iles RA, Burns SP, Coutts GA, and Cowan FM
- Subjects
- Humans, Infant, Newborn, Phenobarbital therapeutic use, Phenytoin therapeutic use, Propylene Glycol, Seizures drug therapy, Brain Chemistry, Magnetic Resonance Spectroscopy, Pharmaceutical Vehicles, Propylene Glycols analysis
- Abstract
Cerebral in vivo proton magnetic resonance spectroscopy of 13 newborn infants displaying seizures and receiving phenobarbitone, in one case supplemented by phenytoin, showed signals from propan-1,2-diol (the injection vehicle for both these anticonvulsants). Subsequent in vitro spectroscopy of cerebro spinal fluid (CSF) from one of these infants also showed signals from this substance. The estimated in vivo propan-1,2-diol concentration (approximately 3 mM) was less than that measured in the CSF sample (14.4 mM). These observations suggest that propan-1,2-diol may accumulate in cerebral tissue and misidentification of its signals in both in vivo and in vitro proton spectra may confuse diagnoses of metabolic or other disorders.
- Published
- 1994
- Full Text
- View/download PDF
192. The role of immunoglobulin binding factors in the pathogenesis and therapy of AIDS.
- Author
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Cowan FM and Madsen JM
- Subjects
- HIV Antibodies immunology, HIV Envelope Protein gp120 immunology, HIV Envelope Protein gp41 immunology, HIV Infections etiology, HIV Infections therapy, HIV-1 immunology, Humans, Receptors, Fc immunology, Staphylococcal Protein A immunology, Suppressor Factors, Immunologic immunology, Acquired Immunodeficiency Syndrome etiology, Acquired Immunodeficiency Syndrome therapy, Lymphokines immunology, Prostatic Secretory Proteins
- Abstract
The human immunodeficiency virus (HIV) gp120 and gp41 envelope proteins and Staphylococcus aureus protein A (SPA) all have Fc receptor (FcR)-like immunoglobulin binding factor (IBF) activity for the Fc constant fragments of human immunoglobulin G (IgG). Viral IBF may contribute to the pathology of HIV by jamming the network of FcR signals that control FcR-dependent immunity. Conversely, the bacterial IBF SPA has anti-retroviral activity that may involve antagonism of the immunopathological action of viral IBF, strongly suggesting IBF may act as a double-edged sword that might be turned against viral invaders.
- Published
- 1994
- Full Text
- View/download PDF
193. Sulfur mustard-increased proteolysis following in vitro and in vivo exposures.
- Author
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Cowan FM, Yourick JJ, Hurst CG, Broomfield CA, and Smith WJ
- Subjects
- Animals, Disease Models, Animal, Guinea Pigs, Humans, Hydrolysis, In Vitro Techniques, Kinetics, Lymphocytes drug effects, Lymphocytes enzymology, Male, Peptides metabolism, Skin enzymology, Skin pathology, Substrate Specificity, Temperature, Endopeptidases metabolism, Mustard Gas toxicity, Skin drug effects
- Abstract
The pathologic mechanisms underlying sulfur mustard (HD)-induced skin vesication are as yet undefined. Papirmeister et al. (1985) postulate enhanced proteolytic activity as a proximate cause of HD-induced cutaneous injury. Using a chromogenic peptide substrate assay, we previously reported that in vitro exposure of cell cultures to HD enhances proteolytic activity. We have continued our investigation of HD-increased proteolytic activity in vitro and have expanded our studies to include an in vivo animal model for HD exposure. In vitro exposure of human peripheral blood lymphocytes (PBL) to HD demonstrated that the increase in proteolytic activity is both time- and temperature-dependent. Using a panel of 10 protease substrates, we established that the HD-increased proteolysis was markedly different from that generated by plasminogen activator. The hairless guinea pig is an animal model used for the study of HD-induced dermal pathology. When control and HD-exposed PBL and hairless guinea pig skin where examined, similarities in their protease substrate reactivities were observed. HD-exposed hairless guinea pig skin biopsies demonstrated increased proteolytic activity that was time-dependent. The HD-increased proteolytic response was similar in both in vitro and in vivo studies and may be useful for elucidating both the mechanism of HD-induced vesication and potential treatment compounds.
- Published
- 1993
- Full Text
- View/download PDF
194. Putative roles of inflammation in the dermatopathology of sulfur mustard.
- Author
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Cowan FM and Broomfield CA
- Subjects
- Animals, Anti-Inflammatory Agents pharmacology, Dermatitis, Contact pathology, Dermatitis, Contact prevention & control, Endopeptidases metabolism, Humans, Lymphoid Tissue drug effects, Lymphoid Tissue immunology, Skin enzymology, Skin pathology, Dermatitis, Contact etiology, Mustard Gas toxicity, Skin drug effects
- Published
- 1993
- Full Text
- View/download PDF
195. MRI: early onset of changes in Wallerian degeneration.
- Author
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Pennock JM, Rutherford MA, Cowan FM, and Bydder GM
- Subjects
- Adult, Brain Ischemia diagnosis, Female, Frontal Lobe blood supply, Frontal Lobe pathology, Humans, Infant, Newborn, Male, Middle Aged, Nerve Fibers, Myelinated pathology, Parietal Lobe blood supply, Parietal Lobe pathology, Brain pathology, Magnetic Resonance Imaging, Wallerian Degeneration
- Abstract
T2-weighted spin echo scans were performed on a neonate and two adults aged 42 and 60 years within 2 weeks of the onset of infarction in the frontoparietal region of the brain. Areas of increased signal intensity were observed in the anterior and posterior limbs of the internal capsule in the infant and in the posterior limbs of the internal capsules in the adults. Although these signal changes were typical of the chronic phase of Wallerian degeneration, their onset was much earlier than the 10-14 weeks previously described for this stage in adults. The low level of myelination of white matter tracts at birth, and the relatively sparse myelination of the parietopontine tract may account for the rapid onset of changes in these patients which more closely follows the time course described pathologically for Wallerian degeneration in unmyelinated fibres.
- Published
- 1993
- Full Text
- View/download PDF
196. Herpes simplex virus infection as a risk factor for human immunodeficiency virus infection in heterosexuals.
- Author
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Cowan FM, Johnson AM, and Mindel A
- Subjects
- HIV Infections complications, Herpes Simplex complications, Humans, Middle Aged, Risk Factors, Sexual Behavior, HIV Infections etiology, HIV-1, Herpes Simplex etiology
- Published
- 1993
- Full Text
- View/download PDF
197. MRI diffusion-weighted imaging of the brain: contributions to image contrast from CSF signal reduction, use of a long echo time and diffusion effects.
- Author
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Oatridge A, Hajnal JV, Cowan FM, Baudouin CJ, Young IR, and Bydder GM
- Subjects
- Brain Diseases diagnosis, Brain Neoplasms diagnosis, Cerebral Hemorrhage diagnosis, Cytomegalovirus Infections diagnosis, Diffusion, Glioma diagnosis, Hematoma diagnosis, Humans, Image Enhancement, Time Factors, Brain anatomy & histology, Cerebrospinal Fluid, Magnetic Resonance Imaging methods
- Abstract
The contributions of CSF signal reduction, use of a long echo time and diffusion weighting to the appearance of pulsed gradient spin echo (PGSE) images are analysed by reference to T2-weighted spin echo and T2-weighted fluid attenuated inversion recovery (FLAIR) pulse sequences. Both PGSE and T2-weighted FLAIR sequences reduce CSF signal and produce very heavy T2 weighting allowing the specific additional contribution produced by the diffusion weighting of PGSE sequences to be recognized. Considerable advantage accrues from CSF suppression with both PGSE and FLAIR sequences through reduction in partial volume effects and artefacts. The very heavy T2 weighting with both these pulse sequences highlights certain white matter tracts and provides high sensitivity to disease. The additional diffusion weighting with PGSE sequences can enhance or reduce white matter tract signals and may enhance or reduce lesion conspicuity relative to the FLAIR sequences. Many of the benefits attributed to the diffusion-weighted PGSE sequence may result from the reduction of the CSF signal and the heavy T2 weighting of the sequence without a contribution from diffusion effects. However, additional anatomical detail, sensitivity to myelination and increased lesion conspicuity may result from the diffusion weighting.
- Published
- 1993
- Full Text
- View/download PDF
198. High signal regions in normal white matter shown by heavily T2-weighted CSF nulled IR sequences.
- Author
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Hajnal JV, De Coene B, Lewis PD, Baudouin CJ, Cowan FM, Pennock JM, Young IR, and Bydder GM
- Subjects
- Adult, Brain pathology, Brain Neoplasms diagnosis, Cerebral Infarction diagnosis, Humans, Infant, Male, Middle Aged, Brain anatomy & histology, Magnetic Resonance Imaging methods
- Abstract
Inversion recovery (IR) sequences with an inversion time (TI) designed to markedly reduce or null the signal from CSF (TI of approximately 2,100 ms at 1.0 T) and a very long echo time (TE) of 240 ms were used to image the brain of two normal adult volunteers, one 34-year-old man with an intrinsic tumor, and one 3-month-old infant with an infarct. Using these very heavily T2-weighted pulse sequences, adult gray and white matter showed similar signal intensity in many areas of the brain, but normal white matter in regions of the centrum semiovale, posterior internal capsule, parietopontile tract, occipitothalamic radiation, and brain stem showed a much higher signal intensity than surrounding gray or white matter. The infant displayed a low signal intensity in myelinated regions in the internal capsule and occipitothalamic radiation and a high signal in unmyelinated white matter. In many of the images there were strong similarities to the distribution of high signal within white matter seen with pulsed gradient spin echo sequences (TE 130 ms) designed to demonstrate effects due to anisotropic diffusion. Arguments are advanced to support the view that the high signal intensity in white matter tracts is due to one or more long T2 components that may be associated with unmyelinated or sparsely myelinated fibres within white matter. The resemblance to diffusion weighted images may reflect the fact that both employ long TEs and both produce a low signal from CSF. If myelin possessed a different susceptibility from axoplasm so that magnetic field gradients were generated around nerve fibres when their orientation was not parallel to B0, diffusion of water might then produce the observed dependence on fibre direction. The high signal regions in white matter are a potential source of confusion in image interpretation, and measurements of T2 in white matter need to be made with these regional variations in mind. The concept of normal appearing white matter also needs to be applied with a knowledge of these differences. The IR sequences used in this study provide a very high T2 dependence with a low signal from CSF and may be useful for detecting disease in the CNS of adults and children.
- Published
- 1992
- Full Text
- View/download PDF
199. Inhibition of sulfur mustard-increased protease activity by niacinamide, N-acetyl-L-cysteine or dexamethasone.
- Author
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Cowan FM, Broomfield CA, and Smith WJ
- Subjects
- Cells, Cultured, Enzyme Activation, Humans, Hydrolysis, Substrate Specificity, Acetylcysteine pharmacology, Dexamethasone pharmacology, Endopeptidases metabolism, Mustard Gas toxicity, Niacinamide pharmacology, Protease Inhibitors pharmacology
- Abstract
The pathologic mechanisms underlying sulfur mustard-induced skin vesication remain undefined. Papirmeister et al. (1985) have postulated a biochemical mechanism for sulfur mustard-induced cutaneous injury involving DNA alkylation, metabolic disruption, and enhanced proteolytic activity. We have previously utilized a chromogenic peptide substrate assay to establish that human peripheral blood lymphocytes exposed to sulfur mustard exhibited enhanced proteolytic activity. In this study, compounds known to alter the biochemical events associated with sulfur mustard exposure or to reduce protease activity were tested for their ability to block the sulfur mustard-increased proteolysis. Treatment of cells with niacinamide, N-acetyl-L-cysteine, or dexamethasone resulted in a decrease of sulfur mustard-increased protease activity. Complete inhibition of sulfur mustard-increased proteolysis was achieved by using protease inhibitors (antipain, leupeptin, and 4-(2-aminoethyl)-benzenesulfonylfluoride). These data suggest that therapeutic intervention in the biochemical pathways that culminate in protease activation or direct inhibition of proteolysis might serve as an approach to the treatment of sulfur mustard-induced pathology.
- Published
- 1992
- Full Text
- View/download PDF
200. HIV testing and assessment of risk of other sexually transmitted diseases.
- Author
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Thompson C, Cowan FM, Bisset CM, and Brettle RP
- Subjects
- Adolescent, Adult, Female, Humans, Male, Mass Screening, Middle Aged, Prospective Studies, Risk Factors, Scotland epidemiology, HIV Antibodies analysis, HIV Seropositivity epidemiology, Sexually Transmitted Diseases epidemiology
- Abstract
The risk factors for infection with the human immunodeficiency virus (HIV) were assessed in individuals attending two different HIV antibody testing clinics: Genitourinary Medicine (GUM) and an HIV counselling and screening clinic (CSC) The risk of acquiring other sexually transmissible infections (STD) was also assessed, and all patients were offered STD screening. Fewer STDs were found in CSC patients than in GUM patients, but the results highlight the need to be aware of the possibility of other STDs whenever and wherever HIV antibody testing is undertaken.
- Published
- 1992
- Full Text
- View/download PDF
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