Thromboelastography with heparinase in orthotopic liver transplantation.

OBJECTIVE: To investigate the role of heparin in the postreperfusion coagulopathy during liver transplantation with heparinase-guided thromboelastography. DESIGN: A prospective, interventional study. SETTING: A university-affiliated hospital. PARTICIPANTS: Twenty-six patients undergoing orthotopic liver transplantation (OLT). INTERVENTIONS: Blood drawn at five intervals for thromboelastography assessment with native (12 patients) or celite blood (14 patients) compared with simultaneous thromboelastography traces with added heparinase. MAIN RESULTS: In the native samples, the prolonged R (reaction) and K (coagulation) time and decreased alpha angle were corrected in heparinase thromboelastograph traces immediately before reperfusion and 10 minutes postreperfusion. In the celite-accelerated samples, the heparinase traces showed correction of the R and K times and alpha angle only at the 10-minute postreperfusion stage. In seven patients who had thromboelastography performed after protamine administration, there were no differences between celite and heparinase-celite traces. CONCLUSIONS: Heparinase-treated thromboelastography offered compelling evidence for the presence of heparin-like activity after liver graft reperfusion. The objective evidence provided by this modification of thromboelastography-guided protamine administration and was useful in identifying one of the many potential causes of postreperfusion bleeding in patients undergoing OLT.

Analysis of training set parallelism for backpropagation neural networks.

Training set parallelism and network based parallelism are two popular paradigms for parallelizing a feedforward (artificial) neural network. Training set parallelism is particularly suited to feedforward neural networks with backpropagation learning where the size of the training set is large in relation to the size of the network. This paper analyzes training set parallelism for feedforward neural networks when implemented on a transputer array configured in a pipelined ring topology. Theoretical expressions for the time per epoch (iteration) and optimal size of a processor network are derived when the training set is equally distributed among the processing nodes. These show that the speed up is a function of the number of patterns per processor, communication overhead per epoch and the total number of processors in the topology. Further analysis of how to optimally distribute the training set on a given processor network when the number of patterns in the training set is not an integer multiple of the number of processors, is also carried out. It is shown that optimal allocation of patterns in such cases is a mixed integer programming problem. Using this analysis it is found that equal distribution of training patterns among the processors is not the optimal way to allocate the patterns even when the training set is an integer multiple of the number of processors. Extension of the analysis to processor networks comprising processors of different speeds is also carried out. Experimental results from a T805 transputer array are presented to verify all the theoretical results.

The first weeks of breast feeding.

PIP: The 2 main causes of the contemporary epidemic of breastfeeding failure appear to be urban life and hospital delivery. In rural areas, the majority of mothers breastfeed successfully. They have much emotional support from experienced women around them, and although some women experience problems, traditional birth attendants are skilled at both preventing and overcoming them. In town, a woman may be surrounded only by young friends as inexperienced as herself and a husband who is impatient of a crying infant. The most obvious solution to any difficulty is a feeding bottle which she can see many modern people using, including some health workers. Hospital delivery contributes to lactation failure by separating the mother and baby to allow them both to "rest," yet mothers who are separated from their babies for even 12 hours stop breastfeeding sooner than mothers who put their baby to the breast immediately after delivery. Possibly the emotional bonding that occurs during the 1st few hours gives a mother the motivation that she needs to persist with breastfeeding when it becomes difficult. In most societies it is customary to let the baby breastfeed immediately, and many traditional birth attendants are aware of how this helps both to stop uterine bleeding and to promote a better flow of milk. In hospitals a baby may be given feeds of formula milk or glucose water, while he/she "waits" for mother's milk to come in. Prelacteal feeds fill a baby's stomach, reduce his/her appetite, and make the baby less willing to suck at the breast. This delays the onset of lactation and increases the dangers of engorgement. If a baby is given his/her prelacteal feeds (or later feeds) from a bottle with a rubber teat, he/she is likely to develop "nipple confusion" and to fail to suck effectively from his/her mother. If hospitals are to be places in which babies may start to feed safely, the staff should let a mother suckle her baby immediately after delivery, and they should let her keep the baby with her and demand feed from the start. The majority of early breastfeeding problems are trivial and are easily if there is someone nearby who knows. Health service administrators should arrange for mothers to have care near home soon after delivery.^ieng

Interpretation of arm circumference as an indicator of nutritional status.

Data from a longitudinal study of 1342 Zambian children aged between 0 and 60 months are used to derive reference standards for mid-upper arm circumference. To determine the sensitivity, specificity, and predictive value of the arm circumference measurement as an indicator of nutritional status, associations between arm circumference and other anthropometric and clinical indicators of nutritional status are presented. Although none of the anthropometric indices accurately reflects the clinical judgement of nutritional status, arm circumference is shown to be similar in accuracy to weight for age and to weight for length as an indicator of clinical malnutrition; it provides a viable alternative to these more cumbersome measurements for use in field surveys.