Plastic particle migration during intravenous infusion assisted by a peristaltic finger pump in an animal model

The contamination of intravenously administered fluid with foreign material has always been of major concern, but the in-vivo impact of silicone embolisation from administration of fluid via a peristaltic finger pump (PFP) has not previously been assessed. To determine whether silicone particles enter the lungs and to review the histological response, 10 rabbits received an IV infusion of 0.9% saline at 10 ml/kg per hour over a 72-h period, via an IVAC 591 PFP. The lungs were analysed for silicone particles with scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDXA). These results were compared with a control group of non-infused animals. Silicone particles were found in 8 of 10 animals in the experimental group and in 2 of 9 control animals, indicating that silicone particles are dislodged during pump-assisted IV infusions. The difference between the control and infused animals was statistically significant using Fisher's exact test (P = 0.023). However, silicone plastic particles in control animals suggest that there is also environmental exposure to silicone in addition to those particles that come from a therapeutic source. The additional finding of elemental silicon (which is one of the constituents of silicone plastic) in both infused and control animals in which silicone plastic was not found indicates that not all elemental silicon in animals reflects the presence of silicone plastic. The clinical significance of each of these two findings is yet to be determined.     

An in vitro study of silicone migration from intravenous fluid tubing

Migration of particulate matter from plastic tubing and solid plastic implants has been documented in a number of studies, including some with the use of cardiac bypass, haemodialysis, and pump-assisted intravenous infusions. In order to ascertain whether silicone embolisation occurs when children have an Ivac 560 pump-assisted IV infusion, we passed 180 ml of pumped fluid through a microfilter and compared the scanning electron micrographs of those filters with unused filters and with others through which a similar volume had been passed without using the pump. The particles on the filters were analysed for their elemental content using energy-dispersive X-ray analysis. In addition, the appearance of the silicone tubing used in the pump over 3 and 72 h was assessed and compared to that of flow-only and unused tubing. More particles were found on the microfilter when fluid had been delivered via the pump than on those through which nonpumped fluid had passed or that were unused. Elemental silicon-containing particles were only found on the filter when a pump had been attached to the IV line. The flow-only and unused tubing were found to have adherent particles on the inner surface that were not seen once the tubing had been used for 3 h in the Ivac 560 pump. Also, after 72 h use, the silicone tubing had a deformed inner layer. The clinical significance of these findings is yet to be determined, but it does appear that silicone embolisation occurs during pump-assisted infusions in children.     

Safety and efficacy of silicone rod frontalis suspension surgery for childhood ptosis repair

PURPOSE: To evaluate the safety and efficacy of silicone rod frontalis suspension surgery for childhood ptosis. METHODS: The authors retrospectively studied 89 consecutive children (110 eyelids) who had silicone rod frontalis suspension surgery for ptosis at Duke University Eye Center from 1983 to 2004. Marginal reflex distance1 (MRD1) elevation of 2 mm or more (vs preoperative MRD1) was considered satisfactory. MRD1 was measured as the vertical distance from the corneal light reflex in primary gaze to the upper eyelid margin. The postoperative eyelid symmetry (< or = 1 mm = satisfactory) was the difference between the MRD1 of the surgical and fellow eyelid. RESULTS: Median age at surgery was 45 months (range: 3 to 223 months) and median follow-up was 17 months (range: 1 to 88 months). Ptosis types (number of eyelids) were unilateral congenital (53), bilateral congenital (30), third nerve palsy (16), Marcus Gunn jaw wink (7), trauma (2), and myasthenia gravis (2). Median MRD1 elevation was 2 mm or greater for all ptosis types, whereas satisfactory postoperative symmetry occurred in 60% of unilateral and 100% of bilateral congenital ptosis cases (last follow-up). Complications occurred in 10 eyelids (9%) and reoperation occurred in 10 eyelids (9%). CONCLUSION: The use of silicone rod frontalis suspension surgery for ptosis repair in pediatric patients is modestly effective, with few complications and easy removal and adjustment.     

Endoscopic subureteric collagen injection (SCIN): a new alternative treatment of vesicoureteric reflux in children

Endoscopic subureteric injection has become an accepted form of treatment for vesicoureteric reflux in children in selected cases. However, the commonly injected substance Teflon has raised doubts as to its long-term safety. Glutaraldehyde cross-linked bovine collagen, which is not associated with the feared side effects of Teflon (granuloma formation, particle migration), seems to be an adequate replacement. At the Departement of Paediatric Surgery of the Basel University Children's Hospital 54 patients with a total of 82 refluxing units were treated with the subureteric collagen injection (SCIN) in the period between June 88 and August 90; 45 patients were female and 9 were male. The average age at treatment was 4.9 years (2 months– 15.2 years). Micturating cystourethrograms performed 3 months after injection showed disapperance of reflux in 61.3% (49 ureters).If improvement to grade I and II reflux was included, the success rate increased to 77.5%. After two SCIN procedures 77.6% of the ureters became free of reflux. Including improvement to grade I and II reflux, the success rate increased to 83.8%. The mean follow-up time was 11.5 months (2–27 months). Injection-related complications were not observed. Although the overall results were not as good as those after surgical correction of reflux and the long-term effects of the collagen implants are not yet known, SCIN seems to be a simple alternative treatment for vesicoureteric reflux in children.     

Pediatric silicone oil surgery

PURPOSE: To evaluate clinical characteristics, surgical aspects, and visual outcomes of pediatric patients who underwent pars plana vitrectomy and silicone oil injection for complicated retinal detachment. PATIENTS AND METHODS: The records of 24 patients (25 eyes) younger than 18 years were retrospectively reviewed. All patients underwent pars plana vitrectomy and silicone oil injection for complicated retinal detachment between January 1995 and June 2004 in the Ophthalmology Department of Dokuz Eylul University, Izmir, Turkey. All patients had follow-up at or beyond 6 months. RESULTS: Nineteen (79.2%) boys and 5 (20.8%) girls were included. Mean age was 12.6 years (standard deviation, +/- 3.5; range, 5 to 17). Five eyes (20%) had blunt ocular trauma. Eleven eyes (44%) had penetrating trauma. Three eyes (12%) had high myopia. Four eyes (16%) had congenital cataract surgery. One eye (4%) had redetachment 1 month after vitreoretinal surgery performed at another clinic. One case had bilateral proliferative vitreoretinopathy with an undefined cause. The retina remained attached in 18 (72%) of 25 eyes at the final examination (17 were totally attached; 1 was partially attached). Mean follow-up was 23.4 months (standard deviation, +/- 20.5; range, 6 to 108). Postoperative visual acuity improved to 1/10 or better only in 6 eyes (24%) at the last examination. CONCLUSION: In pediatric patients with complicated retinal detachment, silicone oil injection for intraocular tamponade is an option for treatment, but visual outcome is poorer than for adults.     

Results of endoscopic subureteral collagen injection for reflux correction in pigs and dogs

The efficacy of endoscopic correction of reflux with the use of Teflon has been proven, but there are safety concerns because of granuloma formation and particle migration. Using glutaraldehyde cross-linked (GAX-) bovine collagen as an alternate biomaterial, animal experiments were performed with 6 female pigs and 20 beagle dogs. Primary and experimentally-induced vesicoureteral reflux was treated by endoscopic injection of bovine GAX-collagen (Zyplast) submucosally at the ureteric orifice. Radiographic controls after 6, 8, or 12 months revealed successful reflux correction in 14 of 19 treated ureters of dogs. After the animals were killed, pathohistological evaluation demonstrated persistence of the collagen depot at the site of injection even after 12 months, although not in all cases, without inflammatory or foreign-body tissue reaction. No evidence of particle migration was found. Invasion of fibroblasts and fibrocytes into the collagen depot and capillary vessel formation appeared the same after the different time intervals, and there was no difference between the two animal species. The biocompatibility of purified bovine GAX-collagen makes it an alternative to Teflon for reflux correction. Offprint requests to: F. Kempter     

Endoscopic treatment of vesicoureteral reflux in children with neuropathic bladder

The authors report on the management of 15 patients with vesicoureteral reflux secondary to neuropathic bladder treated by endoscopic subureteral injection of polytef paste (Teflon) in the first 9 cases and collagen (Zyplast) in the last 6 cases. Their ages ranged from 18 months to 12 years. The degree of reflux ranged from grade II to grade V. The amount of paste injected varied from 0.2 to 1 ml Teflon and from 0.75 to 1.5 ml Zyplast. The endoscopic treatment was completely successful in 12 cases. The risks and benefits of endoscopic treatment versus medical and traditional surgical management are discussed. The endoscopic approach could be a valuable alternative to open surgical repair in vesicoureteral reflux secondary to neuropathic bladder.Presented in Basel, at the International Congress of Endoscopic Paediatric Urology, 13–15 September, 1990     

Successful use of rib grafts for cranioplasty in children

Numerous materials are available for use in cranioplasty including bone, plastics and metals. Rib grafts as a construct for cranial reconstruction offer several advantages: autologous bone source, a formable platform, low infection, regeneration at the donor site and high fusion rates. Criticism of rib graft cranioplasty includes scarring and pain at the donor site, irregular contour at the graft site and graft reabsorption. Since 1988, we have performed rib autograft cranioplasty on 13 patients. Seven females and 6 males combined for an average age of 6 years (11 months to 20 years) at the time of surgery. The mean follow-up from surgery is 27 months (2-48 months), with 11 subjects having at least 12 months. The commonest reasons for cranial reconstruction were: post-traumatic calvarial defect (n = 4), defect from previous craniotomy (n = 3), "growing" skull fracture (n = 2), and defect from previous encephalocele closure (n = 2). Mean defect size was 41 cm(2) (8-144 cm(2)) and average number of ribs harvested was 1.75 (1-3). Simple rib cranioplasty had a mean time in the operating room of 6 h and 30 min. No donor site complications were noted (pneumothorax, significant post-operative pain) and no post-operative infections were encountered. Excellent cranial contour was achieved in each of the 11 patients followed for a minimum of 12 months. One subject required staged reconstructive procedures owing to the size of the defect.     

Dextranomermikrosphären (Deflux) in der endoskopischen Therapie des vesikoureteralen Refluxes

Purpose. Substances currently used for endoscopic correction of vesicoureteric reflux like Teflon, silicone or bovine collagen are critical with regard to biocompatibility. We investigated dextranomer microspheres (Deflux) in the endoscopic therapy of vesicoureteric reflux. Methods and Patients. Deflux was used in 29 children aged 20 months to 13,5 years (40 vesicoureteric units). Effectiveness of treatment was controlled by voiding cystourethrography 3 to 6 months afterwards. Results. Overall, the endoscopic treatment with Deflux was successful in 17 children and 23 vesicoureteric units. Infection associated reflux I°–III° was treated successfully in 17 of 19 children (=89,5%). In contrast, endoscopic therapy was not effective in children with reflux IV° and V° and in children with neurogenic bladder dysfunction. Conclusion. Deflux is an attractive alternative in the endoscopic treatment of vesicoureteric reflux in children. Especially, children with infection associated low-grad reflux may profit from this minimally invasive therapy.     

Central venous catheter infections

When used wisely, central venous catheters are capable of providing vital circulatory access in any patient with a remarkably low risk of infection or major complication. Tunneled silicone catheters are the route of choice for long-term or outpatient use, particularly for oncology or TPN patients; insertion of such a catheter should occur early in the hospitalization of a newly diagnosed patient on chemotherapy. The greatest experience has accrued with the cuffed silicone catheters (for example, Broviac), but the totally implantable devices (for instance, Port-a-cath) may become the device of choice in pediatric outpatients. For infants, small, percutaneously inserted noncuffed silicone catheters appear to offer the greatest safety. Among acute care patients, percutaneous plastic central venous catheters fulfill a vital role but represent an important source of infection. Scrupulous technique, the minimizing of manipulation, and a readiness to replace the catheter at any suggestion of trouble are important to achieving the best results. Within a given design, it is generally best to use the smallest diameter catheter capable of performing the desired tasks. However, on the basis of currently available data, there need be no hesitation to use a multilumen catheter if the care of the patient demands multiple access ports. The various silicone catheters can usually be left in place while infection is treated, although fungal and certain other infections are more likely to require catheter removal. Percutaneous plastic catheters should be removed or changed over a wire if infection is suspected; if tip culture of the removed catheter is positive, and the catheter was replaced over a wire, then the replacement catheter should be promptly removed.     

In vitro bacterial adherence to ventriculoperitoneal shunts

Bacterial adherence to medical devices has been recognized as an important initial step in the infectious process, but it has not been fully elucidated regarding ventriculoperitoneal (VP) shunts. The aim of the present study was to quantitatively determine the adherence in vitro of bacteria known to cause VP shunt infections and to identify factors affecting the process. Clinical isolates studied included Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli. Adherence was examined quantitatively per square centimeter, visualized by electron microscopy and related to slime production and hydrophobicity. Although all four strains adhered to VP shunts, there were marked differences, with S. epidermidis and S. aureus showing the highest adherence (67.0 x 10(3) and 15.2 x 10(3) bacteria/cm(2), respectively). Factors affecting adherence included incubation time and temperature, bacterial concentration, device material (lower for silicone than Teflon), slime production and hydrophobicity. These data might be helpful for devising novel strategies to reduce VP shunt infections.     

Analysis and technical refinements of endoscopic treatment of vesico-ureteral reflux in children with a 40-month follow up

We report our experience with the endoscopic treatment of vesicoureteral reflux by submucosal injection of Teflon in children. During a period of 40 months, 450 children and a total of 678 ureters were treated; 606 ureters were available with a follow-up of more than 3 months and examined by cystography. The overall success rate was 84.2% after one injection and 94.3% after two injections; 96.2% of the primary refluxes disappeared after two injections. We believe that in duplicated ureters and grade IV and V refluxes only one injection should be tried. If this fails we undertake surgical reimplantation. The success rate in neurogenic bladders and failures of previous surgical reimplantations allows surgery to be avoid in these difficult cases. We found seven non-pathological Teflon granuloma calcifications that had no influence on the results. Offprint requests to: P. Sauvage     

Endoscopic treatment of children with vesico-ureteric reflux

Endoscopic subureteric injection of tissue-augmenting substances has become an alternative to long-term antibiotic prophylaxis and open surgery in the treatment of children with vesico-ureteric reflux. Successful elimination of reflux in about 80% of patients after a single injection (and in 90% after a repeat) has been achieved using the foreign-body non-degradable substances Teflon and silicone. Few patients have required open surgery and recurrence of reflux after initial successful treatment has occurred in only 5-10%. Concern has arisen, however, about possible distant migration and granuloma formation after injection of particulate plastic materials. Cross-linked bovine collagen is a biodegradable alternative substance, but with a lower response rate of 60% after the first treatment and a recurrence rate of 10-20%. Dextranomer in sodium hyaluronan is a new biological substance with microparticles with a response rate of 69% after the first injection. Biological substances have caused few complications. Present literature on injection treatment unfortunately focuses on elimination of reflux, with little attention to subsequent frequency of pyelonephritis or to the long-term development of the kidneys. Furthermore, there are no controlled, randomized studies with subureteric injection as one of the treatment alternatives. Thus, although having the advantage of being a minimally invasive procedure that can be performed on an outpatient basis, this technique needs to be tested in a large prospective study with the long-term renal outcome as the main end-point.     

Induced apoptosis of TH2 lymphocytes in asthmatic children treated with Dermatophagoides pteronyssinus immunotherapy

Allergen-specific immunotherapy (IT) has been effectively used for the treatment of asthma. Allergen specific IT induced immune tolerance with induction of TH2 cells anergy remain to be clarified. The aim of this study was to evaluate whether the mite allergen Dermatophagoides pteronyssinus (Dpt) specific IT serially decreased IL-4+/CD4+ (TH2) lymphocytes and induced apoptosis of TH2 lymphocytes in asthmatic children. Sixty Dpt-sensitive asthmatic children were randomly assigned to a received IT and an untreated group. Dermatophagoides pteronyssinus specific IT treated patients were examined at three time points: before IT, after 6 months of an increased dose phase and with maximum tolerated doses after 1 yr. Peripheral blood mononuclear cells (PBMC) were isolated and cultured for 48 h for cellular staining with CD4+, CD45RO cell phenotypes and interleukin (IL)-4 and interferon-gamma expression by fluorescence monoclonal antibodies. Apoptosis was measured using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) method. A simultaneous flow cytometric study using the same permeabilized cell was examined to determine whether apoptosis occurred preferentially in TH2 lymphocytes. The data demonstrated that Dpt specific IT decreased Dpt-specific IgE levels (p < 0.01) after 1 yr of treatment. In addition, decreased CD4+IL-4+ TH2 cells with increased CD4+IFN-gamma+ TH(1) cells were observed at 6 months and 1 yr after IT treatment (p < 0.05). At the same time, apoptosis of CD4+IL-4+ TH2 lymphocytes in the IT group had increased after 1 yr of treatment when compared with the results before treatment (p < 0.001) and after 6 months of treatment (p = 0.046). In addition, CD45RO cells apoptosis mainly occurred after 6 months of IT treatment and after 1-year period of IT treatment (p < 0.05). All of the data suggested that Dpt specific IT decreased Dpt specific IgE and CD4+IL-4+ TH2 lymphocytes with induction apoptosis of CD4+IL-4+ TH2 lymphocytes subsets serially.     

Endoscopic treatment of children with vesico-ureteric reflux

Endoscopic subureteric injection of tissue-augmenting substances has become an alternative to long-term antibiotic prophylaxis and open surgery in the treatment of children with vesico-ureteric reflux. Successful elimination of reflux in about 80% of patients after a single injection (and in 90% after a repeat) has been achieved using the foreign-body non-degradable substances Teflon and silicone. Few patients have required open surgery and recurrence of reflux after initial successful treatment has occurred in only 5-10%. Concern has arisen, however, about possible distant migration and granuloma formation after injection of particulate plastic materials. Cross-linked bovine collagen is a biodegradable alternative substance, but with a lower response rate of 60% after the first treatment and a recurrence rate of 10-20%. Dextranomer in sodium hyaluronan is a new biological substance with microparticles with a response rate of 69% after the first injection. Biological substances have caused few complications. Present literature on injection treatment unfortunately focuses on elimination of reflux, with little attention to subsequent frequency of pyelonephritis or to the long-term development of the kidneys. Furthermore, there are no controlled, randomized studies with subureteric injection as one of the treatment alternatives. Thus, although having the advantage of being a minimally invasive procedure that can be performed on an outpatient basis, this technique needs to be tested in a large prospective study with the long-term renal outcome as the main end-point.     

Prenatal stress and immune recognition of self and nonself in the primate neonate.

The capacity of the neonate to respond to nonself antigens was evaluated in infant monkeys born after normal and disturbed pregnancies. Mixed lymphocyte cultures were used to test the infants' proliferative responses to mitomycin-treated stimulator cells, either from a genetically unrelated animal or from a virally transformed monkey cell line. Periods of daily stress for 6 weeks in mid-late pregnancy (months 3.0-4.5) resulted in a significant decrease in proliferative responses, whereas the same stressor early in pregnancy (months 1.5-3.0) increased responses by the neonate's cells. Similar to the late stress effect, an inhibition of proliferative responses by neonatal cells was induced by dexamethasone administered for 2 days late in pregnancy at 4.5 months after conception, 1 month before term. These findings demonstrate that certain immune responses at birth are extremely sensitive to prior prenatal events. Further, the bidirectional changes indicate that there may be critical periods in gestation when the same extrinsic events have radically different effects on the fetus.     

Potential hazards of exposure to di-(2-ethylhexyl)-phthalate in babies. a review

Many plastic items are made of polyvinylchloride (PVC) blended with plasticizers. The most frequently used plasticizer is di-(2-ethylhexyl)-phthalate (DEHP). DEHP migrates at a constant rate from plastics to the environment: it has been detected in water, soil and food and is therefore considered as a widespread environmental contaminant. Over the past several years, a number of publications concerning toxic effects of DEHP on animals and humans have been reported. Although DEHP is suggested to be of low acute toxicity, long-term exposure, especially in human beings at risk such as pregnant women and children, requires more in-depth studies. If DEHP toxicity in humans were to be confirmed, it would be advisable in the future to replace current PVC plasticizers, especially if they come into contact with babies, with better-quality materials.     

Changes in Lactate Dehydrogenase Isoenzymes Associated with Relapse of Childhood Acute Lymphocytic Leukemia

Twenty-eight children with high-risk acute lymphocytic leukemia underwent monthly serum lactate dehydrogenase (LDH) and WH isoenzyme fraction determinations to examine whether WH isoenzpe fractions change with an increase in the body burden of tumor cells. The 9 patients who relapsed and 5 patients who presented with leukemia during the study period had a slightly lower mean LDH-1 isoenzyme fraction. When the period from 3 months before to 3 months after relapse was examined, significant increases in the LDH-3 isoenzyme fraction and decreases in the LDH-1 and LDH-2 isoenzyme fractions were seen at the time of relapse. These results were highly significant when patients with non-T-cell and T-cell leukemia were combined and when bone marrow and central nervous system relapse was included. The changes at relapse appeared to revert with intensification of chemotherapy. The changes at relapse were not different in magnitude from random variation occurring in patients who remained in remission throughout the study. Although changes in LDH isoenzymes appeared to occur at the time of relapse compared with the periods immediately before and after relapse, these changes were not specific for relapse. LDH isoenzymes do not appear to be useful in predicting relapse in children with leukemia.     

Prognostic value of immunological data, in vitro antibody production, and virus culture in vertical infection with HIV-1

The prognostic value of immunological indices, in vitro antibody production, and virus culture pattern at 3 months of age was estimated in 35 infants infected by HIV-1 from a cohort of 298 babies born to HIV-1 seropositive mothers and followed up from birth. At 1 year old, 15 of these infants were classified as stage P-1 (according to the Centers for Disease Control classification) seven were P-2A, and seven had AIDS. Significantly higher CD8 percentages, lower percentages and absolute value of CD4, and lower CD4/CD8 ratios at 3 months were observed in infants with severe symptoms at 1 year of age when compared with those who were asymptomatic at this age. Seventy seven per cent of infants with a 'rapid' virus culture when 3 months old had developed AIDS or had died by 1 year of age and only 8% of those with 'slow' virus culture had AIDS when 1 year old. Moreover, 100% of those who were asymptomatic at 1 year had a slow virus culture at 3 months. Significant statistical association was found between the virus replication pattern at 3 months and the clinical stage at 1 year of age.     

Recovery of Natural Killer Cells After Chemotherapy for Childhood Acute Lymphoblastic Leukemia and Solid Tumors

Recovery of natural killer (NK) cells after cessation of chemotherapy for childhood acute lymphoblastic leukemia (ALL) and solid tumors was investigated in 25 children aged 3 to 18 years. The numbers of CD3-CD56+, CD16+, and CD8-CD57+ cells in peripheral blood were analyzed with monoclonal antibodies and flow cytometry at 0, 1, 3, 6, 9, and 12 months after discontinuation of therapy. The CD3-CD56+ and CD16+ cell counts of ALL patients (n = 14) were below the mean -1SD values of controls at cessation but normalized within one month due to a rapid 2.1 and 4.5 fold increase, respectively. The CD8-CD57+ cell count of ALL patients was normal compared to controls at cessation. In solid tumor patients (n = 11), the counts of all NK cell phenotypes studied were of normal amount compared to controls at cessation and no vigorous increase occurred after the therapy. NK cell function was determined by killing K 562 target cells in five patients. In the two standard risk ALL patients tested, the activity was still low at 5 months after therapy. In contrast, the function was normal at 1 month (Wilms' tumor), 3 months (Mb Hodgkin's) and 6 months (Burkitt lymphoma). In conclusion, NK cell counts were decreased compared to controls during therapy for ALL, but recovered rapidly afterwards. In spite of normal counts, NK cell function may be impaired for several months. The number and function of NK cells is less affected in solid tumor patients. These differences may reflect the milder immunosuppressive effect of interval cytostatic medication in solid tumor patients when compared to the more intensive continuous therapy in ALL patients. © 1995 Wi1ey-Liss, Inc.