1,721,153 research outputs found
Infants born to mothers seropositive for human immunodeficiency virus. Preliminary findings from a multicentre European study.
No full textAs part of a project within the European Community research activities on acquired immunodeficiency syndrome (AIDS), infants born to human-immunodeficiency-virus-seropositive mothers are being followed up from birth. By October, 1986, 71 infants from Padua, Berlin, and Edinburgh had been followed up to a median age of 6 months (range 1-15 months). Symptoms of AIDS or AIDS-related complex (ARC) had developed in 5, 3 of whom had died. The median age at antibody loss was during the 10th month. An estimated 75% will have lost maternal antibody by 12 months, but loss of antibody did not exclude infection confirmed by virus culture. Numbers were too small to draw conclusions about the risk of AIDS/ARC and mode of delivery or breast-feeding. The study suggested that the risk of AIDS/ARC is higher in infants born to mothers who have AIDS symptoms during pregnanc
Diagnosis of human immunodeficiency virus 1 infection in infants: in vitro production of virus-specific antibody in lymphocytes.
No full textCaesarean section and risk of vertical transmission of HIV-1 infection. The European Collaborative Study
No full textIndirect evidence suggests that a significant proportion of vertical transmission of HIV infection occurs late in pregnancy or during delivery. Caesarean section, therefore, may protect the fetus from infection. We looked at 1254 HIV-infected mothers and their children and the effects of different modes of delivery on transmission risk. We also included a detailed assessment of confounding factors associated with transmission risk. Women who had caesarean sections were more advanced in their disease progression which may cause the protective effect of caesarean section to be underestimated. When this and other potential confounding factors were taken into account, caesarean section was estimated to halve the rate of transmission. This finding is important in the design of studies to evaluate treatments aimed at reducing mother-to-child transmission
Natural history of vertically acquired human immunodeficiency virus-1 infection. The European Collaborative Study
No full textOBJECTIVE: To describe the natural history of vertically acquired human immunodeficiency virus (HIV) infection.
DESIGN: This was a prospective follow-up study.
SETTING: Ten centers of the European Collaborative Study participated.
SUBJECTS: One hundred twenty-four HIV-infected children were born to women known to be infected at or before the time of delivery since 1986.
MAIN OUTCOME MEASURES: Deaths, acquired immunodeficiency syndrome (AIDS), and HIV-related symptoms and signs were assessed.
RESULTS: In this cohort, treatment before the onset of AIDS was not universal. Less than 10% of children were treated with Zidovudine or intravenous gamma globulin before 6 months of age, with a steady increase to about 40% after 3 years of life. An estimated 23% (95% confidence interval: 15% to 31%) of infected children develop AIDS before the age of 1 year, and nearly 40% (27% to 50%) by 4 years. Ten percent (5% to 16%) die before age 1 year and 28% (16% to 41%) before age 5 years. Twenty-four months after the AIDS diagnosis, an estimated 48% (36% to 70%) of the children are still alive. Although after the age of 1 year immunologic abnormalities became increasingly common, the proportion of infected children with significant HIV-related symptoms or signs declined.
CONCLUSION: The progression of disease in this cohort of vertically infected children was not as fast as previously suggested, even though treatment was not widespread. Although infected children have a high risk of developing some manifestation of HIV infection early in life, serious HIV-related symptoms became less frequent with increasing age. This has important implications for health planning and care provisio
Mother-to-child transmission of HIV infection. The European Collaborative Study
No full text271 children born to HIV-infected mothers in 8 European centres are being followed up from birth in a multicentre, collaborative study. By June, 1988, 45% had been followed for over 1 year: 10 had developed AIDS or AIDS-related complex, all by the age of 9 months, of whom 5 had died. 22 other children had symptoms or signs suggestive of HIV infection; of these, 12 had immunological abnormalities, 9 of whom were infected. 5 children had problems not related to HIV, including 3 neonatal deaths. The other 234 children are immunologically normal and clinically well. The median age of antibody loss was 10.3 months, although 1 did not lose antibody until over 18 months. None lost antibody and then became and remained seropositive. Of 100 children followed for more than 15 months, 19 had persistent antibody, and 5 were antibody-negative but presumed to be infected because of virus isolation or antigen detection; these 5 children were clinically and immunologically normal. The estimated vertical transmission rate was 24%
Children born to women with HIV-1 infection: natural history and risk of transmission. European Collaborative Study
No full text600 children born to HIV-infected mothers by June 15, 1990, in ten European centres were followed to study the natural history of HIV infection and the vertical transmission rate. They were seen at birth, every 3 months up to 18 months of age, and every 6 months thereafter. At last follow-up, 64 children were judged to be HIV infected and 343 had lost antibody and were presumed uninfected. The initial clinical feature in infected children was usually a combination of persistent lymphadenopathy, splenomegaly, and hepatomegaly, though 30% of children presented with AIDS, or with oral candidosis followed rapidly by AIDS. An estimated 83% of infected children show laboratory or clinical features of HIV infection by 6 months of age. By 12 months, 26% have AIDS and 17% die of HIV-related disease. Subsequently, the disease progresses more slowly and most children remain stable or even improve during the second year. The vertical transmission rate, based on results in 372 children born at least 18 months before the analysis, was 12.9% (95% Cl 9.5-16.3%). Virus has been repeatedly isolated in an additional small proportion of children (2.5%, 95% Cl 0.7-6.3%) who lost maternal antibody and have remained clinically and immunologically normal. Without a definitive virological diagnosis, the monitoring of immunoglobulins, CD4/CD8 ratio, and clinical signs could identify HIV infection in 48% of infected children by 6 months, with a specificity of more than 99%
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
