Hospital ambulatory pediatric surgery

Since 1990, we have been conducting ambulatory pediatric surgery in an unit established solely for this purpose, supported by a team of kindergarten teachers, pediatric nurses, anesthesiologists and pediatric surgeons. This prospective investigation includes all ambulatory pediatric operations performed in our department from 1990 to 1995. In this time 3665 infants and children between the ages of 6 weeks and 18 years underwent an ambulatory operation. The ratio male to female was 4.1 to 1. The series consists of 1400 inguinal hernias, 722 inguinal testes, 191 hydroceles/funiculoceles, 75 umbilical hernias, 667 phimoses, 70 meatotomies, 59 hemangiomas, 217 endoscopies and 264 other surgical procedures. Postoperative complications defined as secondary hemorrhage, fever, obvious vomiting, urine retention and laryngospasm upon terminating anesthesia accompanied by subsequent vomiting occurred in 59 (1.6%) of all infants and children. Wound infections were seen in 0.48% (17/3517) of all patients. The recurrence rate for inguinal hernias were 0.79% and 1.12% for inguinal testes. Our experience enables us to summarize that a variety of pediatric operations can be performed today as ambulatory procedures. Nevertheless one must be prepared for the occurrence of complications and always have capacities free for inpatient care where adequate observation and treatment are available. Further improvement is necessary in quality management. In the last 20 years only a few data have been published about recurrence rates after pediatric ambulatory operations for inguinal hernias and inguinal testes. Therefore we started a prospective long- term study.     

Dopamine and intestinal mucosal tissue oxygenation in a porcine model of haemorrhage

Haemorrhage is associated with intestinal mucosal hypoxia and impaired gut barrier function. Dopamine increases oxygen delivery to the intestinal mucosa and may thus counteract haemorrhage-induced mucosal hypoxia. Jejunal mucosal tissue oxygen tension (mucosal PO2) and jejunal oxygen saturation of mucosal microvascular haemoglobin (mucosal HbO2) were measured in 14 anaesthetized pigs. Seven animals served as controls (group C) and seven received continuous infusion of dopamine 16 micrograms kg-1 min-1 (group D) while 45% of blood volume was removed in three equal increments. Resuscitation was performed using shed blood and fluid. Mean arterial pressure and systemic oxygen delivery decreasing significantly during haemorrhage and returned to baseline after resuscitation in both groups. Mucosal PO2 decreased from 4.4 to 1.7 kPa after haemorrhage (P < 0.01) and further to 1.5 kPa after resuscitation (P < 0.01) in group C whereas group D showed an increase from 3.9 to 5.9 kPa after the start of the dopamine infusion (P < 0.05), but no significant difference from baseline after haemorrhage (2.3 kPa) (ns) or resuscitation (3.1 kPa) (ns). Mucosal HbO2 decreased from 52 to 32% after haemorrhage (P < 0.05) and increased to near baseline (37%) (ns) after resuscitation in group C whereas group D showed no significant changes from baseline (54%) throughout the experiment. Comparison between groups showed higher mucosal PO2 and HbO2 values for group D animals after the start of the dopamine infusion (P < 0.05 each), after the first two steps of haemorrhage (P < 0.01 each) and after resuscitation (P < 0.05 each). We conclude that i.v. dopamine 16 micrograms kg-1 min-1 improved tissue oxygenation of the small intestinal mucosa during moderate haemorrhage and subsequent resuscitation.     

Purification of selenoprotein Ph from human plasma

There are three selenium-containing proteins in human plasma: glutathione peroxidase (GSH-Px-P), albumin and selenoprotein Ph, the human analogue to selenoprotein P from rat plasma. Selenoprotein Ph was separated from the two other selenium-containing proteins by Heparin Sepharose chromatography and was shown to have about 60-70% of the total plasma selenium, while both GSH-Px-P and albumin contain about 15%. A 2588-fold purification from human plasma was achieved by using a four-step procedure. SDS-PAGE of the purified selenoprotein revealed, besides one contaminant selenium-free protein band at about 70 kDa, one selenium-containing band ranging from 54 to 67 kDa with a maximum at 63 kDa. This microheterogeneity, also recognized by IEF, may be due to the glycprotein nature of the selenoprotein Ph. The determination of the molecular mass of the native protein varied from 65 kDa using gel filtration on Fraktogel HW 55 to 89 kDa on Sephacryl S-200 HR, suggesting an interaction between the gel-matrices and selenoprotein Ph.     

Effects of ketotifen on human lymphocytes in vitro and in vivo

The effects of the antiasthmatic drug ketotifen (CAS 34580-13-7) on human mononuclear leukocytes were studied in vitro and in vivo. In vitro ketotifen concentration-dependently inhibited mitogen-stimulated lymphocyte proliferation. High ketotifen concentrations also inhibited T-lymphocyte mitogen- and adenosine triphosphate stimulated increases in intracellular Ca2+ in lymphocytes and the U937 human monocyte precursor cell line, respectively; this involved inhibition of both Ca2+ influx and intracellular mobilization. In in vivo experiments, treatment of healthy volunteers with 1 mg ketotifen b.i.d. for 7 d did not alter the number or subset composition of circulating lymphocytes. Moreover, the mitogen-stimulated in vitro proliferation of lymphocytes obtained before and after ketotifen treatment in vivo was similar. It is concluded that high ketotifen concentrations can inhibit the activation of resting lymphocytes in vitro but standard ketotifen treatment does not notably affect the number of function of circulating lymphocytes in vivo.     

Microwave induced plasma processing of nuclear waste calcines

Microwave induced plasma processing was used to sinter synthetic Idaho Chemical Processing Plant (ICPP) alumina and zirconia based high level nuclear waste calcines in a nitrogen atmosphere. The microwave densification behaviour of these nuclear waste calcines was observed parallel with identification of the phases formed after sintering. Sintered densities of > 3.20 g cm^–3 were obtained within 10 min of microwave sintering of pure calcines. Glass frit containing calcines showed lower sintering densities (< 2.0 g cm^–3) due to reactions between the frit and volatile substances in both zirconia based and alumina based calcines; prior removal of frit volatiles increased the sintered density. Phases formed in the microwave sintered calcines were identified by X-ray diffraction.     

Elimination of vector parasites in finite element Maxwell solutions

The vector parasite problem is studied in the context of finite-element solutions of Maxwell's equations for driven boundary-value problems. An expanded weak form which combines the divergence equation with the conventional weak form of the double-curl equation is introduced. This form is related to penalty methods where the penalty or weighting factor varies with the dielectric constant. The resulting algebraic system is identical to the Galerkin-Helmholtz operator on homogeneous subregions. Normal and tangential boundary conditions arise in terms of the divergence and curl of the field on the boundary which can be reexpressed as equivalent charges and currents. Computational results show the occurrence of two distinct types of parasitic modes in driven problems and their elimination with the formulation presented. Practical observations concerning the conditions which provoke spurious modes in these problems are reported. Spurious solutions arise from improper or unphysical boundary conditions, and the importance of careful specification of boundary-value problems is illustrated. Most conceptual difficulties with boundary conditions per se are removed when hybrid methods are used to couple the interior finite-element solution to the exterior problem. which focuses attention on the physics of the source distribution     

The neurotrophic analogue of ACTH(4-9) reduces the perineuronal microglial reaction after rat facial nerve crush

Rats bled to a severe condition of volume-controlled hemorrhagic shock were randomly assigned to one of the following treatments: (1) saline, 1 ml/kg i.v.; (2) saline, 0.2 ml/kg per min i.v. for 10 min; (3) ACTH-(1-24), 160 micrograms/kg i.v.; 4) methylprednisolone, 40 mg/kg i.v.; (5) methylprednisolone, 80 mg/kg i.v.; (6) aprotinin, 10,000 KIU/kg i.v.; (7) norepinephrine, 5 micrograms/kg per min i.v. for 10 min; (8) norepinephrine, 10 micrograms/kg per min i.v. for 10 min. All rats treated with saline or with either of the two doses of methylprednisolone, and half of the rats treated with aprotinin, died within the subsequent 2 h. On the other hand, rats treated with norepinephrine, at either dose, or with ACTH-(1-24) were all still alive 2 h later, a similar improvement in cardiovascular and respiratory parameters being obtained with the two treatments. The effect of ACTH on mean arterial pressure was however more sustained throughout the observation period. These results further support the potential usefulness of ACTH-(1-24) as first-aid treatment in cases of severe blood losses.