Moderne Ultraschalltechniken und ihre Anwendungen am kindlichen Harntrakt

In children ultrasound plays a central role in the diagnostic imaging of the urinary tract. It is used most frequently and as a primary diagnostic option. Consequently, innovations in ultrasound technology and ultrasound contrast media have major impact on pediatric urosonography. Harmonic imaging is a modality that produces artifact-free images with high resolution. It has been shown that harmonic imaging is superior to fundamental mode in many urosonographic indications. Color Doppler is an established imaging modality, but its application for diagnosis of stones in the urinary tract, especially in children, is relatively new. The so-called twinkling sign, a color Doppler artifact at the site where one normally expects the acoustic shadow to be, enhances the conspicuity of the stone. A further development is three-dimensional (3D) ultrasound. It offers better volume measurement of the bladder and kidneys than 2D ultrasound. Contrast-enhanced voiding urosonography has already proven to be a valuable alternative in the diagnosis of vesicoureteral reflux. Thus, a significant decrease of radiation exposure has become possible as it replaces the radiological methods. With the introduction of contrast-specific ultrasound imaging modalities, further improvements in voiding urosonography are emerging.     

Intrarenal reflux: diagnosis with contrast-enhanced harmonic US

The objective of this case report is to demonstrate the possibility of visualizing intrarenal reflux (IRR) in children using contrast-enhanced harmonic voiding urosonography (VUS). A 10-month-old girl underwent VUS as part of the work-up of acute pyelonephritis of the right kidney. Before and after intravesical administration of US contrast medium (Levovist) the urinary tract was scanned in harmonic imaging mode. Bilateral vesicoureteric reflux was detected (right grade IV, left grade III). Moreover, at the height of the reflux the right kidney parenchyma turned markedly echogenic, corresponding to massive IRR. The voiding cystourethrography that followed confirmed the results of the VUS.     

Neuroprotective effects of currently used antidotes in tabun-poisoned rats

The neuroprotective effects of antidotes (atropine, pralidoxime/atropine, obidoxime/atropine and HI-6/atropine mixtures) on rats poisoned with tabun at a lethal dose (220 microg/kg intramuscularly; 100% of LD50 value) were studied. The tabun-induced neurotoxicity was monitored using a functional observational battery and an automatic measurement of motor activity. The neurotoxicity of tabun was monitored at 24 hr and 7 days after tabun challenge. The results indicate that atropine alone is not able to protect the rats from the lethal effects of tabun. Three non-treated tabun-poisoned rats and one tabun-poisoned rat treated with atropine alone died within 24 hr. On the other hand, atropine combined with all tested oximes allows all tabun-poisoned rats to survive at least 7 days following tabun challenge. Obidoxime combined with atropine seems to be the most effective antidotal treatment for the elimination of tabun-induced neurotoxicity in the case of lethal poisoning among tested antidotal mixtures. The antidotal mixture consisting of atropine and HI-6 is significantly less effective than the combination of atropine with obidoxime in the elimination of tabun-induced neurotoxicity in rats at 24 hr following tabun challenge. Pralidoxime in combination with atropine appears to be practically ineffective to decrease tabun-induced neurotoxicity at 24 hours as well as 7 days following tabun poisoning. Due to its neuroprotective effects, obidoxime seems to be the most effective and most suitable oxime for the antidotal treatment of acute tabun exposure among currently used oximes. Thus, the replacement of obidoxime by a more effective acetylcholinesterase reactivator for soman poisoning, the oxime HI-6, can to a small extent diminish the neuroprotective efficacy of antidotal treatment in the case of acute tabun poisonings.     

Carbapenems in pediatrics

Antimicrobial resistance is increasing among bacterial pathogens. In particular, organisms producing extended spectrum beta-lactamase enzymes (ESBLs) and AmpC chromosomal beta-lactamase enzymes are resistant to third generation cephalosporins and pose a formidable challenge in the management of seriously ill patients. Carbapenems are a class of broad-spectrum antibiotics with stability against ESBL and AmpC chromosomal beta-lactamases. They are well tolerated by patients. This review will examine the pharmacokinetic and pharmacodynamic properties of two carbapenems imipenem and meropenem and discuss their clinical use in children. References are limited to the English language and extend back to 1980. Sources include computerized databases such as MEDLINE searched using PubMed, and bibliographies of recent articles and books. Approximately 50% of the articles initially reviewed are included in the bibliography. Carbapenems are efficacious in the treatment of a variety of bacterial infections including meningitis, pneumonia, intraabdominal infections, bone, joint and urinary tract infections. The broad spectrum activity and comparatively low toxicity of carbapenems make them valuable therapeutic agents in the treatment of seriously ill patients with bacterial infections. These agents should be used judiciously in order to minimize the risk for development of carbapenem-resistant pathogens.     

A Comparison of the Efficacy of Acetylcholinesterase Reactivators against Cyclohexyl Methylphosphonofluoridate (GF Agent) by in vitro and in vivo Methods

Abstract: The purpose of this study was to compare the therapeutic efficacy of a new acetylcholinesterase reactivator, designated BI-6 (1-(2-hydroxyiminomethylpyridinium)-4-(4-carbamoylpyridinium)-2-butene dibromide), with presently used oximes (pralidoxime, obidoxime, methoxime) and H-oximes (HI-6, HLü-7) by in vitro and in vivo methods. In vitro, methoxime seems to be the most efficacious reactivator of GF agent-inhibited acetylcholinesterase because the phosphonylation of acetylcholinesterase by GF agent markedly increases its affinity for the enzyme. The oxime BI-6 is more efficacious than other presently used oximes (pralidoxime, obidoxime) but its reactivating efficacy does not reach the efficacy of H-oximes tested. On the other hand, obidoxime and pralidoxime appear to be very poor reactivators of GF agent-inhibited acetylcholinesterase because the phosphonylation of acetylcholinesterase by GF agent markedly decreases their affinity to the enzyme. In vivo, H oximes (HI-6, HLü-7) are the most efficacious antidotes for the treatment of acute poisoning with GF agent in rats while the presently used oximes such as pralidoxime and obidoxime are practically ineffective. BI-6 and methoxime are more efficacious than pralidoxime and obidoxime, nevertheless their therapeutic efficacy does not reach the efficacy of H oximes. Our results show that the ability of oximes to reactivate GF agent-inhibited acetylcholinesterase in vitro usually corresponds to their therapeutic effects against GF agent in vivo.     

The long-term changes in liver DNA and total protein contents following low level sarin exposure in rats

1. The changes in contents of DNA and total protein in the liver of the rats exposed to low level sarin by inhalation at 3, 6 and 12 months following the exposure were studied. The influence of sarin on the DNA and protein metabolism in liver was determined by the measurements of incorporation of tritiated thymidine into DNA, the concentration of DNA and total protein. 2. Our results show that not only symptomatic level 3 but also asymptomatic levels 1 and 2 of sarin are able to significantly decrease the incorporation of radiolabelled thymidine without changing total concentrations of DNA as well as protein at three months following sarin exposure. On the other hand, the significant decrease in total contents of DNA and protein in liver without the changes in the incorporation of tritiated thymidine was determined in liver six months following sarin exposure. Practically no significant changes in the metabolism of DNA and protein were observed at 12 months following sarin exposure. 3. Thus, not only clinically manifested intoxication but also low-level, asymptomatic exposure to nerve agents such as sarin is able to influence the metabolism of nucleic acids as well as proteins even several months following the exposure.     

Motor impersistence: a right-hemisphere syndrome

We studied motor impersistence with a standardized clinical test of sustained actions, both in patients with acute focal stroke lesions, who were matched for age and size of lesion, and normal controls. Patients with right-sided lesions had significantly more impersistence than did those with left-sided lesions. The most discriminating tests were eye-closure, mouth-opening, tongue-protrusion, and gaze to the left. Right central and frontal lesions seemed to be more responsible for motor impersistence than were posterior or left-sided lesions. Although motor impersistence is sometimes seen with diffuse cerebral disease, it is also a sign of right-hemisphere lesions; the phenomenon is probably related to mechanisms of directed attention that are necessary to sustain motor activity.     

Voiding urosonography with US contrast agents for the diagnosis of vesicoureteric reflux in children

Studies comparing voiding urosonography (VUS) with voiding cystourethrography (VCUG) and direct radionuclide cystography (DRNC) were analyzed and detailed tables demonstrating the diagnostic values and grading of vesicoureteric reflux (VUR) are presented. Comparative studies of DRNC were too few and did not allow definite conclusions. Using VCUG as the reference, the results of VUS were as follows: sensitivity 57–100%, specificity 85–100%, positive/negative predictive values 58–100%/87–100%, respectively, and diagnostic accuracy 78–96%. With the exception of two studies the diagnostic accuracy reported was 90% and above. In 19% of pelviureteric units (PUUs) the diagnosis was made only by VUS and in 10% only by VCUG. Thus in 9% of PUUs more refluxes were detected using VUS. In 73.6% the reflux grades were concordant in VUS and VCUG. Reflux grade was found to be higher with VUS than with VCUG in 19.6% of PUUs. In 71.2% of PUUs with grade I reflux on VCUG, the reflux was found to be grade II and higher on VUS. The common selection criteria for VUS as the primary examination for VUR currently include (a) follow-up studies, (b) first examination for VUR in girls, and (c) screening high-risk patients.