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Biomedical subjects

M Barker

Publications and source records attributed to M Barker.

At least 55 records · Page 3Linked to original sources
PubMed1999

Assessment of the feasibility of conducting population prevalence studies of chronic renal failure according to ethnic group: a survey of clinical biochemistry laboratories in Greater London and south east England.

The planning of renal replacement therapy is based on assessment of population need for the white population, but uses historical trends in treatment uptake for black and Asian ethnic minority groups, for whom the incidence of chronic renal failure (CRF) is not known. Epidemiological studies of CRF are based upon follow-up of plasma creatinine results obtained from clinical biochemistry laboratories. We conducted a postal questionnaire survey of UK National Health Service (NHS) and private clinical biochemistry laboratories in Greater London and the south east of England to arrange the design and test the feasibility of carrying out a study to determine ethnic-specific rates of CRF. Fifty-five NHS laboratories (90%) and 19 private laboratories (57%) responded. Few pathology computer systems recorded ethnic group, patient post code, or diagnosis; although 31 of the laboratory computers (42%) were linked with the hospital Patient Administration System which could supply these data. Approximately 5.5 million electrolyte profiles and 20 million individual renal function tests are carried out annually in south east England. Ninety per cent of those were performed within NHS laboratories, implying that a study can use NHS sources alone without risk of any undue bias. Sixty laboratories (81%) included creatinine in their routine electrolyte profile, which would be a requirement for any study. Thirty-one laboratories (42%) archived tests within 1 year of entry, which would rule out a retrospective study design. A prospective study is feasible and should be carried out as soon as is practicable.

Clinical Laboratory Information Systems↗
PubMed1998

Phosphate supplementation in young men: lack of effect on calcium homeostasis and bone turnover.

OBJECTIVE: To examine the effect of phosphate supplements on calcium homeostasis and bone turnover in young men. DESIGN: Study 1 was a randomised, controlled, cross-over trial of 1000 mg elemental phosphate given for one week, with a standard diet of 800 mg/d each of calcium and phosphorus. Study 2 was an escalating dose study of 0, 1000, 1500 and 2000 mg/d elemental phosphate, each given for one week, with a standard diet of 1000 mg/d each of calcium and phosphate. SETTING: Northern General Hospital, Sheffield. SUBJECTS: Study 1, 10 healthy men ages 19-32 y. Study 2, 12 healthy men ages 19-38 y. INTERVENTIONS: Sodium acid phosphate tablets each containing 500 mg elemental phosphorus (16.1 mmol/d), given with meals. RESULTS: Study 1, administration of 32.2 mmol/d phosphorus resulted in a mean increase of 13.2 mmol/d urinary phosphorus, a mean decrease of 1.1 mmol/d urinary calcium, and a mean increase of 7 ng/mL in serum intact PTH. There were no changes in serum phosphate, osteocalcin or urinary N-telopeptide excretion. Study 2, administration of 64.4 mmol/d phosphorus resulted in a mean increase of 27.2 mmol/d urinary phosphorus, a mean decrease of 2.4 mmol/d urinary calcium, with no change in serum phosphate, PTH or urinary deoxypyridinoline. CONCLUSIONS: Phosphate supplementation of the diet does not affect bone turnover in young men.

Adult↗
PubMed1998

Trends in intentional injury deaths in children and teenagers (1980-1995).

BACKGROUND: The aim of the study was to describe patterns and trends in intentional injury death rates in children and teenagers. METHODS: Analyses were carried out on data from the Office of National Statistics on all intentional injury deaths in people aged 0 to 19 years, in England and Wales, from 1980 to 1995. Trends in death rates were examined using Poisson regression modelling, and class-specific death rates were estimated using the Registrar General's Standard Classification of Occupations. RESULTS: Between 1980 and 1995, there has been a substantial fall in the unintentional injury death rate, but no reduction in the intentional injury death rate. Intentional injuries made up 13 per cent of injury and poisoning deaths in 1980, and 25 per cent of such deaths in 1995. Each year in England and Wales an average of 335 children and teenagers die as a result of homicide, suicide and injuries of undetermined intent. Older teenagers (15-19 years) account for 70 per cent of intentional injury deaths, children 0-4 years account for 18 per cent, and children 5-15 years account for 12 per cent. Of the 5361 intentional injury deaths, 45 per cent were classified as injury undetermined whether accidentally or purposely inflicted, 35 per cent were classified as suicide, and 20 per cent were classified as homicide. With the exception of suicide, there are steep social class gradients for each category of intentional injury. The homicide rate for children in social class V is 17 times that for children in social class I. For all intentional injury, homicide, suicide and injuries of undetermined intent, the relative risk of death for manual vs. non-manual was higher for the four year period 1992-1995 than in the four year period 1980-1983. CONCLUSIONS: Intentional injury is responsible for an average of 335 deaths of children and teenagers each year in England and Wales. Unlike for unintentional injury, there has been no reduction in death rates from intentional injury, which now accounts for 25 per cent of all injury deaths. There is a steep social class gradient in intentional injury death rates, which has widened over the period 1980-1995.

Adolescent↗
PubMed1997

Herpes virus (KSHV) associated Kaposi sarcoma in a 3-year-old child with non-HIV-induced immunodeficiency.

UNLABELLED: A 3-year-old boy of German descent suffered from two episodes of Streptococcus pneumoniae meningitis within 2 months. One month previously, the first skin lesion of Kaposi sarcoma (KS) had been observed behind his right ear. During the following 2 years KS disseminated not only mucocutaneously but also to visceral organs. Immunological evaluation revealed severe lymphocytopenia with reduced helper/suppressor T-cell ratio and impaired humoral immune response to pneumococci. Extensive laboratory tests gave no evidence for known immunocompromising infections. However, recently described DNA sequences from a Kaposi sarcoma-associated herpesvirus (KSHV) could be identified within skin tissue. As chemotherapy failed to stop tumour progression the patient was referred for bone marrow transplantation. Eighteen months later the KS is in remission and the patient in a good general condition. CONCLUSION: The case supports the hypothesis that KSHV is involved in the aetiology of KS. Bone marrow transplantation is possibly a therapeutic option for KS in patients with immunodeficiency not related to human immunodeficiency virus infection.

Bone Marrow Transplantation↗
PubMed1997

Randomised trial comparing a policy of early with selective amniotomy in uncomplicated labour at term.

OBJECTIVE: To compare two management policies: rupture of the fetal membranes when women are in normal labour or leave them intact as long as feasible. SETTING: The labour ward of a city university hospital. DESIGN: Automated randomised clinical trial. PARTICIPANTS: 1540 women in uncomplicated term labour. Data on labour duration, blood loss, oxytocin use and fetal condition were collected from 1132 women. Some data from nulliparous women has been presented earlier by the UK Amniotomy Group. MAIN OUTCOME MEASURES: Duration of labour, Apgar score, fetal morbidity and maternal morbidity including perineal injury, mode of delivery, epidural rates and the total number of vaginal examinations in the first stage of labour after amniotomy. INTERVENTIONS: Amniotomy at the next vaginal examination or amniotomy only if indicated. The median cervical dilatation at membrane rupture was 2 cm greater in the first group. RESULTS: A policy of routine amniotomy in labour had no measurable advantage over selective amniotomy for parous women (difference = 4 min) but shortened labour in nulliparous women by 1 h (Mann-Whitney U test: P < 0.05). There was a suggestion of a higher caesarean section rate (OR 1.9; 95% CI 0.9-3.5), and there were more vaginal examinations after membrane rupture in the group allocated routine amniotomy. There were no measurable differences in oxytocin use, fetal condition at birth, retained placenta rates, blood loss, pain or analgesia requirements. CONCLUSION: Routine amniotomy may shorten the first labour but not subsequent ones. There is a suggestion that routine surgical interference may be harmful by increasing the risk of caesarean section, and this agrees with data from other trials (common odds ratio 1.2; 95% CI 0.92-1.6).

Adult↗
PubMed1997

Birth weight and body fat distribution in adolescent girls.

OBJECTIVE: To examine the association between birth weight and body fat distribution in a group of adolescent girls. DESIGN: A total of 216 white girls who were born in Southampton had their heights, weights, waist and hip circumferences, and skinfold thicknesses measured when they were aged between 14 and 16 years. RESULTS: The girls who were smallest at birth, but who were fattest at time of measurement were the most centrally obese. In girls whose body mass index was above the median (21 kg/m2), the subscapular to triceps skinfold ratio rose by 9% for every kilogram decrease in birth weight. Among overweight girls, with a body mass index over 25, the ratio rose by 27% for every kilogram decrease in birth weight. CONCLUSION: In adolescent girls, the tendency to store fat on the trunk rather than the limbs, seems to be programmed by growth in fetal life, and is most evident in those who are overweight.

Adipose Tissue↗
PubMed1997

Side effects of methylphenidate and dexamphetamine in children with attention deficit hyperactivity disorder: a double-blind, crossover trial.

OBJECTIVE: To compare the side effect profiles of methylphenidate (MPH) and dexamphetamine (DEX) in children with attention deficit hyperactivity disorder (ADHD), as well as to determine which symptoms are genuine adverse effects of stimulant medication, as opposed to aspects of the child's underlying behavioral phenotype. DESIGN: Double-blind, crossover study. SETTING: Pediatric teaching hospital ambulatory behavior clinic. SUBJECTS: A total of 125 children with ADHD with a mean age of 104.8 months. INTERVENTIONS: Subjects received DEX (0.15 mg/kg/dose) and MPH (0.3 mg/kg/dose) twice a day for 2 weeks each in a randomized order. OUTCOME MEASURES: The Barkley Side Effects Rating Scale (17 symptoms; 0 = absent, severity rated from 1 to 9) was completed by parents at baseline and at the completion of each trial fortnight. RESULTS: Subjects' parents reported a significantly greater mean number (8.19) and mean severity (4.08) of "side effects" before commencing the trial than during the MPH period (number 7.19; severity 3.24), but not the DEX period (number 7.64, severity 3.73). The mean severity (but not mean number) was greater on DEX than on MPH. DEX caused more severe insomnia and appetite suppression compared with the baseline rating. Appetite suppression was the only item rated more severe on MPH than at baseline. Six side effects were significantly more severe on DEX than MPH: insomnia, irritability, proneness to crying, anxiousness, sadness/unhappiness, and nightmares. None were more severe on MPH than DEX. Overall, both MPH and DEX were well tolerated by most subjects, with only four subjects discontinuing the trial period because of severe adverse effects (2 -1.6%- on each stimulant). CONCLUSIONS: Many symptoms commonly attributed to stimulant medication are actually preexisting characteristics of children with ADHD and improve with stimulant treatment. At the doses investigated, both DEX and MPH caused appetite suppression, and DEX caused insomnia. Negative emotional symptoms were more severe on DEX than MPH.

Adolescent↗
PubMed1997

Methylphenidate versus dexamphetamine in children with attention deficit hyperactivity disorder: A double-blind, crossover trial.

OBJECTIVE: To compare methylphenidate (MPH) and dexamphetamine (DEX) in a sample of children with attention deficit hyperactivity disorder (ADHD). METHOD: A total of 125 children with ADHD received both MPH (0.3 mg/kg twice daily) and DEX (0.15 mg/kg twice daily) for 2 weeks a double-blind, crossover study. Outcome measures were Conners' Parent Rating Scale-Revised, Conners' Teacher Rating Scale-Revised, a Parent Global Perceptions questionnaire, the Continuous Performance Test, and the Barkley Side Effects Rating Scale. RESULTS: There were significant group mean improvements from baseline score on all measures for both stimulants. On the Conners' Teacher Rating Scale-Revised, response was greater on MPH than DEX on the conduct problems and hyperactivity factors, as well as on the hyperactivity index. On the Conners' Parent Rating Scale-Revised, anxiety was the only factor to differ significantly, in favor of MPH. Parents rated 73% of subjects as globally improved on MPH and 69% improved on DEX, compared with baseline. Overall, 46% of parents chose MPH as the preferred drug, compared with 37% who chose DEX. On the Continuous Performance Test, there was no difference in the number of correct responses or errors between the two drugs. CONCLUSIONS: Most children with ADHD improve significantly on both MPH and DEX. There was a slight advantage to MPH on most measures.

Adolescent↗
PubMed1997

Speech recognition performance of pediatric Clarion patients.

OBJECTIVE: To evaluate the speech performance of children with the Clarion Multi-Strategy Cochlear Implant. PATIENTS: Prelingually deafened children who had received the Clarion implant. METHODS: The Spondee and Monosyllable Word Identification subtest of the Early Speech Perception test, the Glendonald Auditory Screening Procedure (GASP), and the Phonetically Balanced Kindergarten test (PB-K) were administered to subjects 3 and 6 months after implantation. RESULTS: At 3 months, subjects' performance was higher than preoperatively with hearing aids. At 6 months, performance improved further. Scores were higher on the ESP and GASP than on the PB-K. The scores indicate better levels of speech recognition than were obtained with older implant processing strategies. Subjects varied considerably in their performance. The results are preliminary because of the small sample.

Adolescent↗
PubMed1996

Fumonisin B1 toxicity in male Sprague-Dawley rats.

Male rats were gavaged with fumonisin B1 (FB1) once daily for 11 consecutive days at doses of 0, 1, 5, 15, 35, and 75 mg FB1/kg body weight. Urine osmolality (at 5-75 mg FB1/kg) and organic ion transport in kidney slices (at 5-75 mg FB1/kg) were reduced. Urinary excretion of protein (at 15-75 mg FB1/kg) and of the enzymes LDH (at 5-75 mg FB1/kg), NAG (at 5-75 mg FB1/kg) and GGT (at 15-75 mg FB1/kg) were increased. These findings were indicative of glomerular and tubular toxicity. Histopathologic changes in the kidney consisted of necrosis of tubular epithelia of variable extent accentuated in the inner cortex. These changes were present at 1 and 5 mg FB1/kg and were more pronounced at 15-75 mg FB1/kg. Serum enzymes indicative of hepatotoxicity (ALT, GGT) were elevated compared to controls at 75 mg FB1/kg only. There were noticeable increases in mitotic figures in hepatocytes at 35-75 mg FB1/kg, while single cell necroses were increasingly numerous from 15-75 mg FB1/kg. The kidneys were considered to be the primary target organs in this study.

Acetylglucosaminidase↗
PubMed1996

Growth hormone and aging change rat liver fatty acid binding protein levels.

OBJECTIVE: Rat liver fatty acid binding protein (FABP) is believed relevant to understanding of homeostasis in lipid metabolism and lipid related diseases. Relatively little is known about endocrine control of FABP production. Thus, we examined endocrine effects on its hepatic content. METHODS/RESULTS: Hypophysectomy of 300-325 g males caused statistically significant drops of FABP levels averaging 62.2% and 67.0%, expressed g/liver or 100 g/body weight, 30-52 days after surgery. Cortisol administration (3.8 mg/kg, daily, 32-36 days) did not significantly alter this effect of hypophysectomy. Recombinant human growth hormone (GH, 2.0 U/kg, b.i.d, 17-20 days) greatly decreased the effect of hypophysectomy on FABP but had no effect in intact males. Supporting the control of FABP content by GH, FABP levels decreased significantly in 12-13 and 16-22 month old males, but not in growing, 4-6 or 10-11 month old males. FABP levels in 12-13.5 month old females also dropped significantly compared to 4-6 month old females. DISCUSSION: The importance of the data to metabolism, growth, and aging is discussed.

Aging↗
PubMed1996

Injuries and the risk of disability in teenagers and young adults.

OBJECTIVE: To examine the risk of disability from unintentional injury in teenagers and young adults. METHODS: Analyses of data from the National Child Development Study, a follow up study of 98% of all children born in England, Scotland, and Wales in one week in March, 1958. In 1981, 12,537 study participants, 76% of the original cohort, were asked about unintentional injuries since age 16 years requiring hospital treatment, and whether these injuries resulted in permanent disability. RESULTS: 62% of men and 26% of women reported at least one accident since age 16 resulting in injury that required hospital treatment. Of these accidents, 3.2% caused permanent disability. The risk of disability increased with accident frequency. Injuries requiring hospital admission carried the highest risk of disability (9.7%). However, 54% of permanent disability reported by men and 74% reported by women resulted from injuries treated as outpatients. Road traffic accidents caused 42% of admissions and 31% of disability. Fractures constituted 21% of all injuries but were responsible for 32% of permanent disabilities. Of the permanent disabilities resulting from work related accidents, 82% involved the hand. Of the permanent disabilities resulting from accidents in the home, 32% involved the hand. CONCLUSIONS: The targeting of prevention strategies towards the major causes of injury mortality may have a smaller impact on population levels of injury related disability. Non-life threatening injuries, in particular injuries to the hand and limb fractures, resulting from accidents in the workplace, the home, and during sports, make a significant contribution to the prevalence of permanent injury related disability in young adults.

Accidents↗