Correlation of umbilical cord blood haematopoietic stem and progenitor cell levels with birth weight: implications for a prenatal influence on cancer risk

We examined the relation with birth weight and umbilical cord blood concentrations of haematopoietic stem and progenitor populations in 288 singleton infants. Across the whole range of birth weight, there was a positive relation between birth weight and CD34+CD38− cells, with each 500 g increase in birth weight being associated with a 15.5% higher (95% confidence interval: 1.6–31.3%) cell concentration. CD34+ and CD34+c-kit+ cells had J-shaped relations and CFU-GM cells had a U-shaped relation with birth weight. Among newborns with ⩾3000 g birth weights, concentrations of these cells increased with birth weight, while those below 3000 g had higher stem cell concentrations than the reference category of 3000–3499 g. Adjustment for cord blood plasma insulin-like growth factor-1 levels weakened the stem and progenitor cell–birth weight associations. The positive associations between birth weight and stem cell measurements for term newborns with a normal-to-high birth weight support the stem cell burden hypothesis of cancer risk

Correlation of umbilical cord blood haematopoietic stem and progenitor cell levels with birth weight: Implications for a prenatal influence on cancer risk

We examined the relation with birth weight and umbilical cord blood concentrations of haematopoietic stem and progenitor populations in 288 singleton infants. Across the whole range of birth weight, there was a positive relation between birth weight and CD34+CD38- cells, with each 500 g increase in birth weight being associated with a 15.5% higher (95% confidence interval: 1.6-31.3%) cell concentration. CD34+ and CD34+c-kit+ cells had J-shaped relations and CFU-GM cells had a U-shaped relation with birth weight. Among newborns with ≥3000 g birth weights, concentrations of these cells increased with birth weight, while those below 3000 g had higher stem cell concentrations than the reference category of 3000-3499 g. Adjustment for cord blood plasma insulin-like growth factor-1 levels weakened the stem and progenitor cell-birth weight associations. The positive associations between birth weight and stem cell measurements for term newborns with a normal-to-high birth weight support the stem cell burden hypothesis of cancer risk. © 2008 Cancer Research UK

Revisões sistemáticas de antibioticoprofilaxia em cesarianas Systematic reviews of antibiotic prophylaxis in cesareans

O objetivo do trabalho foi analisar a evidência científica disponível sobre os efeitos da antibioticoprofilaxia em cesarianas. As presentes revisões sistemáticas compreenderam um exame detalhado da qualidade do desenho e da execução assim como da heterogeneidade clínica entre os ensaios. A meta-análise dos ensaios placebo-controlados (27 estudos) apontou eficácia aproximada de 65% para ambos os desfechos estudados, endometrite e infecção da ferida cirúrgica (IFC), correspondendo a uma queda da incidência de 11% e 5%, respectivamente. As análises de sensibilidade mostraram efeitos sumários semelhantes aos observados para o conjunto dos ensaios. O subgrupo dos 12 ensaios de cesáreas não eletivas indicou benefício importante da antibioticoprofilaxia para ambos os desfechos, correspondente a uma queda de 14% (endometrite) e 5% (IFC). Para cesáreas eletivas (dois ensaios), não foi mostrado benefício relevante. A evidência obtida dos ensaios comparativos de doses foi limitada devido a falhas metodológicas importantes e ao pequeno número de pacientes envolvidas (três ensaios). Os ensaios comparativos de antimicrobianos (sete estudos) não evidenciaram diferença de eficácia entre os dois esquemas analisados, cefalosporinas de 1ª e de 2ª geração.<br>This study reviews the available evidence on the efficacy of antibiotic prophylaxis in cesarean sections. The study included a detailed analysis of the quality of design and performance and the clinical heterogeneity of selected clinical trials. Meta-analysis of placebo-controlled trials estimated an efficacy of some 65% for the two study endpoints, endometritis and surgical wound infection, corresponding to a decrease in infection rates of some 11% and 5%, respectively. Sensitivity analyses showed summary effects similar to those observed for all studies. Results for the non-elective cesarean sections subgroup (12 studies) indicated a relevant benefit for both endpoints, corresponding to a decrease in incidence rates of some 14% (endometritis) and 5% (surgical infection wound). For elective surgeries (two trials), no relevant benefit was found. Evidence from comparative trials on number of doses was limited due to important methodological shortcomings and to the small number of patients enrolled (three trials). Comparative drug trials (seven studies) did not show evidence of different performance between first and second-generation cephalosporins