A retrospective analysis of microbial contaminants in outdated random- donor platelets from multiple sites

BACKGROUND: Platelet components contaminated with bacteria are an important source of transfusion-associated bacterial sepsis. Estimates of contamination rates vary widely (0-10%) and are highly controversial. The present study, designed with stringent testing regimens, retrospectively determined the prevalence of microbial contaminants in platelets from four collection regions. STUDY DESIGN AND METHODS: During a 9-month period, outdated platelet units were assayed by spreading aliquots from the unit, and from thioglycollate broth medium inoculated with part of the unit, onto 5-percent sheep blood agar media. Cultures were examined after 72-hour incubation at 37 degrees C, and, if bacterial growth was present, the assay processes were repeated with fresh inocula. Units were considered contaminated only if repeatedly positive. RESULTS: Four (0.08%) of 4995 units sampled were contaminated, two with Corynebacterium sp. and one each with Propionibacterium acnes and Aspergillus terreus. Contaminants were present at low, subclinical levels and were detected only after amplification in thioglycollate. The contaminated units were cultured 1, 2, 3, and 7 days after expiration. CONCLUSION: Contamination rates were low and did not vary by region. The identification of A. terreus suggests the role that transfusion may play in transmitting fungal infections should be reassessed. The persistent detection of contaminated platelet units supports the need for a test to detect clinically relevant levels of microbial contaminants in blood components.     

A randomized, controlled trial of nurse home visiting to vulnerable families with newborns

OBJECTIVE: This project aimed to evaluate the impact of a home visiting programme that targeted families where the child, for environmental reasons, was at great risk of poor health and developmental outcomes. METHODOLOGY: Women in the immediate postpartum period were recruited to a randomized double-blind controlled trial on the basis of self-reported vulnerability factors and were randomly assigned to receive either a structured programme of nurse home visiting, supported by a social worker and paediatrician (n = 90), or assigned to a comparison group receiving standard community child health services (n = 91). Parenting stress and maternal depression were measured at enrollment and at 6 weeks. Preventive health behaviour, service satisfaction and home environment outcomes were tested at 6 weeks, as were child health outcomes. RESULTS: At six weeks, women receiving the home-based programme had significant reductions in postnatal depression screening scores as well as improvements in their experience of the parental role and improvement in the ability to maintain their own identity. Maternal-infant interactions were more likely to be positive, with significantly higher (better) scores in aspects of the home environment related to optimal development in children, particularly maternal-infant secure attachment. Intervention group mothers were significantly more satisfied with the community child health service. CONCLUSIONS: This form of intervention for families is effective in promoting secure maternal-infant attachment, preventing maternal mood disorder and is welcomed by the families receiving it. These findings may predict long-term benefits for the healthy development of children otherwise at risk of a range of poor health and development outcomes.     

共培养下后交叉韧带成纤维细胞中MMPs的基因表达

目的研究后交叉韧带(posterior cruciate ligament,PCL)成纤维细胞与滑膜细胞共培养下,2种细胞之间的交流对PCL成纤维细胞中基质金属蛋白酶MMP-1、2、3表达及活性的影响。方法分为共培养组和单培养组:①用显微镜观察共培养24 h后细胞的活性和迁移率。②分别培养6 h后,提取总RNA,逆转录PCR;实时荧光定量PCR对人后交叉韧带成纤维细胞MMP-1、2、3基因的表达进行半定量和定量分析。③共培养处理1、2、3 d后收集培养上清液,用明胶酶谱法检测MMP-2的活性。结果共培养使PCL细胞和滑膜细胞较单层细胞培养迁移率分别增高了(43.1±0.1)%和(76.2±0.2)%(P<0.01)。与单培养相比,共培养组明显增加了MMP-2的基因表达,但降低了MMP-1、3的基因表达。酶谱结果表明共培养增加了MMP-2活性(P<0.05)。结论共培养能够促进细胞的迁移以及调节细胞中MMP-1、2、3的表达情况。