Design flaw can convert commercially available continuous syringe pumps to intermittent bolus injectors

OBJECTIVE: To investigate if unexpected behaviour of neonatal and paediatric patients connected to syringe pumps could be explained by transient elevation of these devices. DESIGN: Five different commercially available syringe-pumps were set at an infusion rate of 1 ml/h and then subjected to a vertical displacement manoeuvre (height 1 m). The actual delivered infusion volumes in association with the displacement manoeuvre were measured by a high precision weight scale connected to a computer. SETTING: A medical technology laboratory in a university hospital. MEASUREMENTS AND RESULTS: Elevation of the devices resulted in a rapid bolus injection of 0.19-2.28 ml. Returning the devices to their original positions resulted in an aspiration into the system of 0.06-0.34 ml. The times both for bolus injection and for aspiration into the system were less than 1 min in all cases. The updown manoeuvre was followed by a period with zero infusion ranging from 8 to 105 min. CONCLUSIONS: Design flaws in the construction of syringe pumps can expose patients to substantial danger following vertical displacement if potent drugs are being infused. If potent drugs are infused, care should be taken not to change the vertical position of the syringe pump even for short periods of time. Before buying new equipment, the authors recommend that the delivery characteristics of these devices should not only be tested during ordinary bench testing but should also include the reaction to a vertical displacement manoeuvre.     

The influence of dietary iron on zinc in rat

Cortical bone remodeling rates for rib samples from three archaeological populations and a modern autopsy sample were determined using an algorithm developed by Frost (Frost [1987a] Calcif. Tissue Res. 3:211-237). When plotted against the relative antiquities for population samples, histomorphometric variables; i.e., activation frequency (mu rc), net bone formation (netVf,r,t), and mean annual bone formation rate (Vf,r,t), exhibit a concordant trend of increased cortical bone remodeling activity levels over time. Two intensive foraging populations, Windover and Gibson, are similar for all bone remodeling parameters and have the lowest remodeling activity levels among the samples. The more recent Ledders sample, which is reported to practice agricultural subsistence, is consistently intermediate between these and a modern autopsy sample. Although there appear to be differences in bone formation rates among the populations it is concluded that these differences cannot be attributed to differences in bone remodeling rates among the populations, but rather are reflecting different effective ages of adult compacta for their ribs. These findings suggest that the earlier populations, particularly Windsor and Gibson, appear to have reached skeletal maturity at an older age than observed for modern.     

Control and diagnosis in the biotechnical systems of artificial clearance

Controlling and diagnostic processes in the bioengineering artificial clearance systems despite of the procedures applied, their functional use and design seem to occur in the artificial organs, each of them consists of controlling and actuating processors ensuring their homogeneous (material, energy-producing, informational) or combined interaction with the patient's body. Centralized control over artificial clearance is proposed by using universal controlling processes which are informationally connected with the operator, the central computer and other controlling processes of the bioengineering system.     

Management of E. coli dependent factorial diseases in weaning piglets

The most important postweaning factorial diseases are at least partly caused by E. coli. The term postweaning coli complex can be subcategorized into the following manifestations: postweaning diarrhoea, edema disease, postweaning wasting and hemorrhagic gastroenteritis. In the presented study the effect of prophylactic zootechnique alone and zoo- and biotechnique in combination was evaluated during the first weeks postweaning. The results showed that combined zoo- and biotechnique is superior to simple zootechnique regarding food conversion (1.41 kg versus 1.73 kg), average daily weight gain (390 g versus 325 g) and postweaning piglet mortality (3.1% versus 4.9%). It is the opinion of the authors that combined postweaning zoo- and biotechnique should be performed in such pig production units where ETEC and/or SLTEC are present.     

Hepatic vein thrombosis. Diagnostic and therapeutic difficulties

Budd Chiari syndrome (liver vein thrombosis) may be a diagnostic and therapeutic problem. On the basis of four different cases we review the major diagnostic and therapeutic principles involved. Imaging techniques are necessary in order to establish the diagnosis. Ultrasound examination with Duplex doppler is usually sufficient, but MR angiography is also useful. Treatment options are thrombolysis, surgery or liver transplantation. What treatment is selected will depend on the clinical situation and the prognosis.     

Pediatric craniocerebral trauma. Special characteristics, therapy and prognosis

The mortality rate after traumatic brain injury in children ranges between 2.5% and 21%. Standardized diagnostic procedures and therapeutic strategies for the management of traumatic brain damage are presented in this article. Children with traumatic cerebral lesions have a better clinical outcome than head-injured adults. Optimized medical management and intensive rehabilitation may help to reduce the frequency of mental retardation and physical disability following such injuries in children.     

Restenosis and arterial remodelling after coronary angioplasty

Restenosis after coronary angioplasty (PTCA) is a complex process and is still the major problem, despite improvements in equipment and technique. Thrombus formation and intimal hyperplasia have been considered to be the main causes of the development of restenosis after primary successful angioplasty. As yet, pharmacological trials to prevent restenosis have failed to prevent it, despite the fact that the therapy has been aimed at reducing thrombus formation and intimal hyperplasia. Several new angioplasty devices have been developed. Series of observations and a few controlled trials have demonstrated restenosis rates similar to those obtained with conventional balloon angioplasty, except in the case of stent implantation, which appears to be promising. Intravascular ultrasound studies have provided new insight and a more complete understanding of the process leading to restenosis. Vascular remodeling is now considered as an important pathogenetic factor. It consists of a change in the cross-sectional vessel area and may involve an actual constriction of the artery. This may lead to lumen-narrowing and finally restenosis with minimal neointimal formation. In this review we summarise the literature on the restenosis process and the current status of the clinical trials aimed at preventing restenosis.     

Intrauterine transfusions influence fetal leukocyte counts and subsets

Histamine is an important mediator in allergic reactions, gastric acid secretions, and neurotransmission in the central nervous system. Basophils and mast cells are the main sources of histamine, which is formed from L-histidine by histidine decarboxylase (HDC). However, the regulatory mechanism of HDC in these cells remains unclear. We examined the regulation of HDC activity and gene expression using a unique human mast cell line, HMC-1, after stimulation with phorbol 12-myristate 13-acetate (PMA) or ionomycin. HDC activity was increased from 52.1+/-0.4 (mean+/-standard deviation) to 154+/-6.9, or 105.6+/-6.2 pmol/min/mg protein (n = 3), 4 hours after stimulation with PMA (10 ng/mL) or ionomycin (10[-6] M). Although actinomycin D had no effect on this increase, cycloheximide completely inhibited the increase caused by these stimuli. The population of HMC-1 cells containing HDC protein was increased after stimulation with either PMA or ionomycin as evaluated by immunocytochemical analysis with anti-HDC antibody as a marker. HMC-1 constitutively expressed HDC mRNA, and its level was not increased with these stimuli. These results suggest that the increase of HDC activity in HMC-1 induced by PMA or ionomycin is regulated at the translational level.