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Biomedical subjects

C Power

Publications and source records attributed to C Power.

At least 127 records · Page 7Linked to original sources
PubMed1995

Adult outcome of normal children who are short or underweight at age 7 years.

OBJECTIVES: To evaluate the adult growth outcome (at age 23) of children who are short or underweight at age 7 years in whom no identifiable pathological cause exists for their poor growth. DESIGN: Longitudinal follow up of a birth cohort. SETTING: The national child development study (1958 birth cohort) of Great Britain. SUBJECTS: 523 children with a height or a weight below the fifth centile at age 7. Of these, 70 (13.4%) were excluded because they had a longstanding illness that could account for their poor growth. The remaining 453 subjects, who were followed to age 23, provided the base group from which those with additional data, such as parental height, were obtained. RESULTS: 55/174 (31.6%) boys who were short at age 7 became short men; 60/211 (28.4%) girls who were short at age 7 became short women. Among boys who were underweight at age 7, 46/160 (28.7%) were still underweight at age 23, while 61/200 (30.5%) girls underweight at age 7 became underweight women. Having short parents did not increase the probability of being small as an adult. Children with delayed puberty were as likely to remain small as those in whom puberty was not delayed. CONCLUSIONS: One in three normal children who was short or underweight at age 7 became a short or underweight adult. This informs the management of short children and may be valuable when prolonged growth hormone treatment for short stature is being considered.

Adolescent↗
PubMed1995

HIV Dementia Scale: a rapid screening test.

HIV dementia has an annual incidence of 7% after AIDS development and eventually affects 20% of all HIV-infected persons. Accurate and early diagnosis of HIV dementia can lead to optimized therapeutic and management decisions. The purpose of this study was to design a valid instrument to identify HIV dementia. Five groups totalling 152 outpatients were evaluated; HIV-seronegative (SN) (n = 34); asymptomatic HIV-seropositive (ASX) (n = 38); AIDS, nondemented (AIDS) (n = 53); AIDS, mildly demented (Dm) (n = 39); and AIDS, severely demented (Ds) (n = 7). None had CNS opportunistic infections or delirium due to drug intoxication or systemic illness at the time of testing. Patients were evaluated with three different screening instruments: (a) the newly developed HIV Dementia Scale (HDS), (b) the Minimental State Exam (MMSE), and (c) the Grooved Pegboard (PB). Mean HDS scores (+/- SD) (maximum = 16) for each group were as follows: SN, 14.9 +/- 1.69; ASX, 14.1 +/- 1.72; AIDS, 12.8 +/- 3.17; Dm, 8.0 +/- 3.81; and Ds, 3.5 +/- 2.94. A Receiver-Operating Characteristic curve was used to derive an optimal HDS cut-off score of < or = 10 for identifying HIV dementia, with a sensitivity of 80%, specificity 91%, and positive predictive value 78%. The efficiencies of each instrument for identifying HIV dementia were as follows: HDS-84%, PB-86%, and MMSE-72%. The HDS is a reliable and quantitative scale that is superior to other widely used bedside tests such as the MMSE for identifying HIV dementia.

AIDS Dementia Complex↗
PubMed1995

HIV-1 associated dementia: clinical features and pathogenesis.

HIV-1 infection is characterized by multiple neurological syndromes occurring at all stages of infection. HIV-1-associated dementia, however, is the most devastating CNS consequence of AIDS because of its poor prognosis and functional impairment. A clinical triad of progressive cognitive decline, motor dysfunction, and behavioural abnormalities typifies this subcortical dementia which eventually affects 15 to 20% of AIDS patients. Neuroimaging, CSF studies and neuropsychological testing are frequently required in diagnosing HIV-associated dementia, to exclude other conditions including psychiatric illnesses, opportunistic diseases and systemic disorders. The pathogenesis of HIV dementia is uncertain and there is evidence that multiple mechanisms of neurological injury occur. These mechanisms include: the role of neurovirulent strains of HIV; the potential neurotoxicity of HIV gp120, nitric oxide and quinolinic acid; immunologically mediated CNS injury through the action of cytokines and arachidonic acid metabolites; and altered blood-brain barrier permeability. A collective approach involving clinical studies, in vitro assays and animal models will provide greater insight into the pathogenesis and the rational development of therapy for HIV dementia.

AIDS Dementia Complex↗
PubMed1995

Weight-for-height indices of adiposity: relationships with height in childhood and early adult life.

BACKGROUND: The expense and inconvenience of accurate assessment of fat/lean body mass have engendered a reliance on weight-for-height indices in epidemiological investigations; indices which are independent of height have been considered desirable. METHODS: The relationship between weight-for-height and height was examined using the 1958 birth cohort, National Child Development Study, at ages 7, 11, 16, 23 and 33 years. For each age the sample was divided into a number of height groups; underweight, overweight and obesity were defined by relative weight (RW) and body mass index (BMI) in childhood and adulthood respectively. RESULTS: In childhood the variance of RW showed substantial and systematic associations with height. Both underweight and overweight/obesity were related to height: patterns differed by age and sex, being most evident at age 7 in both sexes, continuing at age 11 (but more so in boys), and disappearing by age 16. At age 23, underweight was more prevalent and overweight and obesity less prevalent in the taller groups due to a linear correlation between BMI and height. At age 33 obesity was less prevalent in taller groups, particularly in women. CONCLUSIONS: These findings have implications for studies of obesity comparing groups which differ in height, for example, different cohorts or social classes. In the short term, interpretation of such results should take account of the phenomenon described. In the longer term, information is needed on the relationship between height and more precise assessment of adiposity to confirm the findings of the current analysis.

Adolescent↗
PubMed1995

Evaluation of two recombinant Maedi-visna virus proteins for use in an enzyme-linked immunosorbent assay for the detection of serum antibodies to ovine lentiviruses.

Defined segments of the gag polyprotein and transmembrane envelope glycoprotein from Maedi-visna virus were expressed as glutathione S-transferase fusion proteins in Escherichia coli and evaluated singly and in combination for use in an enzyme-linked immunosorbent assay (ELISA). Two hundred sixty field serum specimens from 15 sheep flocks were tested in parallel with recombinant and whole-virus antigens, and the relative sensitivities and specificities of the recombinant antigens were calculated. When the recombinant gag and transmembrane proteins were used in combination, a sensitivity of 97.4% and a specificity of 99.4% relative to whole-virus antigen were observed, indicating the utility of these proteins in diagnostic testing.

Animals↗
PubMed1995

Asthma, enuresis, and chronic illness: long term impact on height.

OBJECTIVE: To determine whether common conditions in early childhood, such as asthma and psychosocial illness (mainly enuresis), affect height during later childhood and in adult life. DESIGN: Longitudinal follow up of subjects in the 1958 British Birth Cohort Study. Data from the birth survey and ages 7, 11, 16, and 23 were used. SUBJECTS: 12,537 subjects remaining in the study at age 23, representing 76% of the target population, cohort members still alive and resident in Britain. RESULTS: Heights of children with allergic, acute or psychosomatic illness, or asthma/wheezy bronchitis did not differ by age 7 from those of children without such illnesses. When asthma was graded by severity, there was a trend (not significant) for the severe group to be shorter at ages 16 and 23. Although children with a chronic illness by age 7 were on average almost 0.5 cm shorter than children without such illnesses, this difference was reduced by half and was not significant after adjusting for maternal height, birth weight, parity, and social class at birth. However, a marked and long lasting effect was found for children with psychosocial illness who at age 7 were significantly shorter, by a mean of 0.77 cm. Within this group, enuretic children with a problem at age 11 were more than 1 cm shorter in adulthood, even allowing for other height related factors. CONCLUSIONS: Common childhood illnesses do not appear to affect height, either in the short or in the long term, although exceptions include chronic illness and enuresis. The value of height as an indicator of child health status in an industrialised country such as Britain requires further reassessment.

Adolescent↗
PubMed1994

Birth weight and later socioeconomic disadvantage: evidence from the 1958 British cohort study.

OBJECTIVE: To investigate the relation between birth weight and socioeconomic disadvantage during childhood and adolescence in a birth cohort study. DESIGN: Longitudinal analysis of birth weight in relation to social class, household amenities and overcrowding, and financial difficulties as reported by parents at interview when participants were aged 7, 11, and 16 years; and receipt of unemployment or supplementary benefits as reported by participants at age 23. SUBJECTS: Male participants in the 1958 birth cohort (national child development study) born to parents resident in Great Britain during the week of 3-9 March 1958. Data on birth weight and financial difficulties between birth and 23 years were available for 4321; data on housing conditions and social class at ages 7, 11, and 16 years were available for 3370. MAIN OUTCOME MEASURES: Socioeconomic disadvantage at later ages in men weighing 6 lb (2721g) or under at birth compared with those weighing over 6 lb and between fifths of the distribution of birth weight. RESULTS: Cohort members who weighed 6 lb or under at birth were more likely to experience socioeconomic disadvantage subsequently. Those in lower fifths of the distribution were more likely to experience socioeconomic disadvantage. CONCLUSION: Low birth weight is associated with socioeconomic disadvantage in childhood and adolescence. Studies of the association of indicators of early development and adult disease need to take into account experiences right through from birth to adulthood if they are to elucidate the combination of risks attributable to developmental problems and socioeconomic disadvantage.

Adolescent↗
PubMed1994

Inducible inhibition of eukaryotic gene expression.

A regulatable binary expression system for eukaryotes was recently developed based on the tetracycline repressor and its operator. Here we show that this system can be successfully applied to express antisense RNA and completely inhibit gene expression in a tetracycline-repressible fashion.

DNA, Complementary↗
PubMed1994

Health and social inequality in Europe.

In most European countries health has been shown to be linked to social circumstances--gradients in health status have persisted for decades, despite major changes in the principal causes of death. In central and eastern Europe life expectancy has stagnated since the mid-60s, whereas in the West it has increased; but even in the West it is related to income distribution. Social differences in mortality in men are three times as large in some countries as in others, and are influenced by factors other than conventional risk factors. Substantial declines in mortality and morbidity could result from a narrowing of health inequalities even when differences in health risk between social groups are comparatively small. Policies to reduce health inequalities can be introduced in smaller communities and organisations such as the school and workplace. National policies are variable; factors generating inequalities require action across several policy areas.

Europe↗
PubMed1994

CD11/CD18 and ICAM-1 expression in a murine foreign body granulomatous lung model.

The expression of leukocyte adhesion molecules (Leu-CAM; CD11/CD18 family) and ICAM-1 was studied on bronchoalveolar lavage (BAL) cells and lung tissue sections from a mouse lung granulomatous model. When foreign body lung granuloma were induced in mice by intratracheal injection of 1.5 x 10(4) Sephadex G-50 beads, total and differential BAL cell counts demonstrated a maximal recovery of macrophages and neutrophils at 3 days. Indirect immunoperoxidase staining patterns indicated that intratracheal challenge with beads activated BAL cells and upregulated expression of CD11b, ICAM-1, and CD18 antigenic markers on macrophages and neutrophils when compared with BAL cells from saline controls. Immunohistochemical staining also confirmed the presence of CD11b on activated macrophages and neutrophils around the beads and of the ICAM-1 antigen in the lung parenchyma of bead challenged mice.

Animals↗
PubMed1994

Immunological/physiological relationships in asthma: potential regulation by lung macrophages.

There is now a consensus that T-cell-mediated inflammation and eosinophil activation in the bronchial wall contribute to the pathogenesis of asthma. However, the relationship between these immunopathological mechanisms and the observed physiological aberrations remain unclear. Here, Len Poulter and colleagues identify the links between T-cell-mediated inflammation and bronchial hyperresponsiveness, and propose a hypothesis for asthma pathogenesis in which the combination of immunological and physiological abnormalities may result in the promotion of disease. Furthermore, they suggest that an integral factor in the prevention of this process is the regulation of bronchial T-cell reactivity by a population of immunosuppressive macrophages.

Asthma↗
PubMed1994

Demented and nondemented patients with AIDS differ in brain-derived human immunodeficiency virus type 1 envelope sequences.

Human immunodeficiency virus (HIV) dementia is a common clinical syndrome of uncertain pathogenesis in patients with AIDS. In several animal models of retrovirus-induced brain disease, specific viral envelope sequences have been found to influence the occurrence of central nervous system disease. Therefore, to search for unique envelope sequences correlated with HIV dementia, we studied 22 HIV-infected patients who were neurologically assessed premortem and classified into demented (HIVD) (n = 14) and nondemented (ND) (n = 8) groups. Using DNA from autopsied brain and spleen, we amplified, cloned, and sequenced a 430-nucleotide region including the V3 loop and flanking regions. All brain-derived clones in both clinical groups showed marked homology to the macrophage-tropic consensus sequence within the V3 loop. Two amino acid positions within (position 305) and outside (position 329) the V3 region showed significant divergence between the two clinical groups. At position 305, a histidine was predominant in the HIVD group and was not observed in the ND group, but a proline was predominant in the ND group and was not observed in the HIVD group. Similarly, at position 329, a leucine was predominant in the HIVD group but rarely observed in the ND group, whereas an isoleucine was predominant in the ND group at this position. In addition, the HIVD group had 21 amino acid residues at specific positions that were unique relative to the ND group, whereas only 2 residues at specific positions were unique to the ND group. These data suggest that distinct HIV envelope sequences are associated with the clinical expression of HIV dementia.

AIDS Dementia Complex↗
PubMed1994

Neutrophil collagenase in sputum from patients with cystic fibrosis.

The potential role of neutrophil elastase in causing lung damage and exacerbating the inflammatory response in cystic fibrosis (CF) has received considerable attention. Although another potent neutrophil-derived enzyme, collagenase, is implicated in tissue destruction in several interstitial lung disorders, there has been no reference to this enzyme in CF. The objective of this study was to determine whether neutrophil collagenase is present in active form in CF sputum and, if so, whether it is related to disease severity. High levels of active collagenase were detected in sputum from patients with CF, and the majority of the enzyme present was of neutrophil origin. In a group of 16 patients with CF, negative relations between sputum collagenase activity and Shwachman score (r = -0.55, p < 0.05) and FEV1 (r = -0.59, p < 0.02) were noted, indicating an association between high collagenase activity and severity of disease. A positive correlation was observed between sputum collagenase and elastase activity (r = 0.62, p < 0.05). These results suggest that both neutrophil elastase and collagenase may play a significant role in lung destruction in CF.

Adolescent↗
PubMed1994

Cytomegalovirus encephalitis in acquired immunodeficiency syndrome (AIDS).

Cytomegalovirus encephalitis (CMVE) is frequently diagnosed only at postmortem because its specific clinical features have not been fully identified. We have described the clinical, radiologic, and laboratory features of CMVE in a retrospective review of 14 autopsy-confirmed cases of CMVE and compared them with a control group of demented acquired immunodeficiency syndrome (AIDS) patients without CMVE. CMVE was more common among homosexual men, and a subacute onset was more typical (mean duration of presenting symptoms was 3.5 weeks versus 18 weeks in demented controls). Median survival times were 4.6 weeks for CMVE and 28 weeks for controls. CMVE was accompanied by prominent systemic CMV infection at autopsy, including CMV adrenalitis (92%), CMV pneumonitis (42%), systemic Mycobacterium avium intracellulare (MAI; 58%), and CMV retinitis (58%). Hyponatremia and MAI bacteremia were found in 58% of CMVE cases. Polymerase chain reaction (PCR) of CSF samples identified CMV genome in 33% of CMVE cases. CMVE was associated with periventricular enhancement on CTs and periventricular lesions with meningeal enhancement on MRI scans. CMVE should be particularly suspected in homosexual men presenting with subacute encephalopathy who have had AIDS for more than 1 year and have a history of systemic CMV infection. Other features supporting the diagnosis of CMVE include periventricular lesions, hyponatremia, and identification of CMV genome in CSF by PCR.

AIDS Dementia Complex↗