Serum immunoreactive erythropoietin of children in health and disease

Serum immunoreactive erythropoietin (siEPO) was determined in cord serum from neonates (n=97, gestational age 36–43 weeks), in healthy children from birth to adolescence (n=260) and in children with haematological (n=30), renal (n=10) and congenital heart diseases (n=70). In healthy children siEPO levels decreased after birth (geometric mean cord siEPO 35.6 mU/ml with 95% range of 17–56 mU/ml in eutrophic, nondistressed fetuses) and reached lowest values during the first 2 months (geometric mean siEPO 11.5 mU/ml). Thereafter siEPO levels increased slightly and were constant between 2 months and adolescence. The geometric mean siEPO for healthy children after birth was 18.8 mU/ml with 95% range of 7–47 mU/ml. These estimates were not significantly different from normal adult values. In newborns with fetal distress (n=15) cord siEPO was significantly elevated (geometric mean 63.0 mU/ml;P<0.001). In children with haematological disease, siEPO and Hb concentration were inversely correlated (log siEPO (mU/ml)=4.1–0.20×Hb (g/dl);r=–0.62;P<0.0005). This relationship was significantly different in children with chronic renal failure (log siEPO (mU/ml)=0.67+0.035×Hb (g/dl);r=0.50;P=0.1). In children with heart disease the geometric mean siEPO was 19.2 mU/ml with 95% range 8–65 mU/ml for cyanotic (SaO₂<94%) and 17.7 mU/ml with 95% range of 12–36 mU/ml for acyanotic patients. In this group siEPO values were inversely correlated to the arterial oxygen content (log siEPO (mU/ml) =1.61–2.04×oxygen content (l/l);r=–0.28;P<0.02).     

Evaluation of superficial papillary ablation by endoscopic lasers in an ex vivo kidney model

BACKGROUND AND PURPOSE: Endoscopic examinations of stone-forming kidneys show a coincidence of plaques and microliths on the surface of and within papillary epithelial tissue. These calcifications are thought to be precursors of calcium oxalate urolithiasis. We hypothesized that minimally invasive endoscopic laser ablation of microliths and necrotic cell layers enables epithelial regeneration and prevents recurrent urolithiasis. The aim of this study was to determine the most suitable laser type and dose intensity for selective superficial cell ablation. MATERIALS AND METHODS: Conventional Nd:YAG (1-40 W) or Ho:YAG (0.5-3 J/single impulse) lasers were used endoscopically on an ex vivo blood-perfused porcine kidney model. Defined doses were applied to the papillary surface in the contact and noncontact modes for 10 to 30 seconds. Papillae were excised after treatment and histopathologically analyzed in continuous sections. Lesions were microscopically assessed with the aid of a Leica Quantimed computer program. RESULTS: Depending on the time and dose, vaporization by the Nd:YAG laser caused large tissue defects and coagulation necrosis at energy levels over 5 W (contact and noncontact mode). Lower energy levels with tissue contact produced only superficial cell defects (<20 cell layers) but more extensive coagulation necrosis, whereas no histologic effects were observed at the same energy level without contact. In contrast, independent of delivered energy but dependent on time, Ho:YAG laser application caused pure tissue loss without relevant coagulation necrosis. The generation of small lesions (6-10 cell layers) without tissue contact was possible at energy levels under 2 J. CONCLUSIONS: Selective superficial papillary cell ablation is possible. Low-energy Nd:YAG treatment in the contact mode and Ho:YAG treatment in the noncontact mode led to superficial vaporization with no (Ho:YAG) or minimum (Nd:YAG) coagulation defects.     

Whole-body vibration exposure study in U.S. railroad locomotives--an ergonomic risk assessment

Whole-body vibration exposure of locomotive engineers and the vibration attenuation of seats in 22 U.S. locomotives (built between 1959 and 2000) was studied during normal revenue service and following international measurement guidelines. Triaxial vibration measurements (duration mean 155 min, range 84-383 min) on the seat and on the floor were compared. In addition to the basic vibration evaluation (aw rms), the vector sum (av), the maximum transient vibration value (MTVV/aw), the vibration dose value (VDV/(aw T1/4)), and the vibration seat effective transmissibility factor (SEAT) were calculated. The power spectral densities are also reported. The mean basic vibration level (aw rms) was for the fore-aft axis x = 0.18 m/sec2, the lateral axis y = 0.28 m/sec2, and the vertical axis z = 0.32 m/sec2. The mean vector sum was 0.59 m/sec2 (range 0.27 to 1.44). The crest factors were generally at or above 9 in the horizontal and vertical axis. The mean MTVV/aw was 5.3 (x), 5.1 (y), and 4.8 (z), and the VDV/(aw T1/4) values ranged from 1.32 to 2.3 (x-axis), 1.33 to 1.7 (y-axis), and 1.38 to 1.86 (z-axis), generally indicating high levels of shocks. The mean seat transmissibility factor (SEAT) was 1.4 (x) and 1.2 (y) and 1 (z), demonstrating a general ineffectiveness of any of the seat suspension systems. In conclusion, these data indicate that locomotive rides are characterized by relatively high shock content (acceleration peaks) of the vibration signal in all directions. Locomotive vertical and lateral vibrations are similar, which appears to be characteristic for rail vehicles compared with many road/off-road vehicles. Tested locomotive cab seats currently in use (new or old) appear inadequate to reduce potentially harmful vibration and shocks transmitted to the seated operator, and older seats particularly lack basic ergonomic features regarding adjustability and postural support.     

Retropupillary fixation of the iris claw lens in aphakia. 1 year outcome of a new implantation techniques

INTRODUCTION: There are several surgical options available for the correction of aphakia. We investigated if retropupillary fixation of an iris claw lens is a method combining the advantages of posterior chamber implants with a new low-risk method of intervention. PATIENTS AND METHODS: An iris claw lens was implanted in 48 eyes in the plano-convex direction (model 205 Y). For the calculation of the IOL power we estimated an A-constant of 116.8. The lens was pushed via a 5-mm wide corneal incision vertically in the anterior chamber and was fixed in the retropupillary position after turning in the horizontal direction. After aspiration of the viscoelastica the corneal incision was closed by a 10-0 nylon suture. RESULTS: The implantation was successful in all patients. A visual improvement was noted in 27 patients (56.2%), an unchanged visual acuity was seen in 18 patients (37.5%) while 3 patients (6.2%) showed a loss of visual acuity. A cystoid macular edema was found by fluorescein angiography in two cases. Leakages in the area of the enclavation were not seen. SUMMARY: The retropupillary fixation of an iris claw lens seems to have the advantages of a true posterior chamber implantation with a low intra- and postoperative risk profile. The easy implantation process with this technique could replace the normally applied sclera suture fixed implantation of a posterior chamber lens as the method of choice.     

Clinical aspects and molecular genetics of the Jervell- and Lange-Nielsen Syndrome

In contrast to the Romano-Ward (R-W) syndrome, the Jervell and Lange-Nielsen (J-LN) syndrome is an autosomal recessive inherited disease characterized by QT-prolongation in the electrocardiogram (ECG) and recurrent syncopal attacks which are also typical for the R-W syndrome, but also by congenital deafness. Recently, defect alleles in the genes for KCNQ1 and KCNE1 have been identified in patients with the J-LN syndrome. These genes may be causative for the R-W syndrome as well but in J-LN patients, they are only present in the homozygote or compound heterozygote form. In the present paper, we review the clinical and genetic similarities and differences of the J-LN and the R-W syndrome as well as the diagnostic and therapeutic management of these patients and their family members.