Untersuchungen über die Brauchbarkeit der Blutvolumenbestimmung mit dem Volemetron

Ohne ZusammenfassungVortragender:M. Schmolke-Freiburg i. Br.     

Gastric acid secretion in conscious miniature pigs

Summary Gastric acid secretion was studied in 5 miniature pigs provided with a chronic gastric fistula. Basal secretion did not change during the growth of the animals. Histamine, carbachol, and pentagastrin produced a dose-dependent volume and acid response. The highest peak acid output (PAO) was achieved with histamine. The maximal peak volume output after histamine was only exceeded by carbachol which was due to an excessive salivation. The maximal PAO after carbachol and pentagastrin as well as the maximal peak volume output after pentagastrin were very low. The poor secretory responses to carbachol and pentagastrin are discussed in the light of possible inhibitory mechanisms or of drug-receptor-interactions.Supported by a grant from the Deutsche Forschungsgemeinschaft.     

Tau-Protein Ein potentieller biologischer Indikator zur Früherkennung der Alzheimer-Krankheit

Zusammenfassung Bei 40 Alzheimer-Patienten, 5 Patienten mit Demenzen anderer Ursache und 36 kognitiv unauff?lligen Kontrollpersonen wurde das Tau-Protein im Liquor cerebrospinalis bestimmt. Von den Alzheimer-Patienten befanden sich 19 in einem sehr leichtgradigen Stadium der Krankheit (Summenwert im Mini-Mental-State-Test 25 bis 28 Punkte). Auch bei diesen wurde gegenüber den Kontrollpersonen eine signifikante Erh?hung von Tau gemessen. Eine weniger ausgepr?gte Erh?hung von Tau zeigte sich bei den Patienten mit anderen Demenzen. Bei den Alzheimer-Patienten fand sich kein quantitativer Zusammenhang zwischen der Erh?hung von Tau und dem Schweregrad der Demenz oder dem zerebralen Perfusionsdefizit, bestimmt mit SPECT. Die Ergebnisse sind ein Hinweis, da? Tau auch im pr?dementiellen Stadium der Alzheimer-Krankheit erh?ht sein k?nnte und sich als biologischer Indikator für die Früherkennung eignet.      

Chemopreventive N-(4-hydroxyphenyl)retinamide (fenretinide) targets deregulated NF-{kappa}B and Mat1A genes in the early stages of rat liver carcinogenesis

Cell-cycle deregulation is an early event of hepatocarcinogenesis. We evaluated the role of changes in activity of nuclear factor kappaB (NF-kappaB) and some related pathways in this alteration, and the interference of N-(4-hydroxyphenyl)retinamide (HPR), a retinoid chemopreventive for various cancer types, with these molecular mechanisms and the evolution of preneoplastic liver to cancer. Male F344 rats, initiated according to the 'resistant hepatocyte' model of liver carcinogenesis, received weekly 840 nmol of liposomal HPR (SL-HPR)/100 g body wt or empty liposomes, between 5 and 25 weeks after initiation. Inhibition of DNA synthesis and induction of apoptosis occurred in pre-cancerous lesions, 7-147 days after starting SL-HPR, and a decrease in carcinoma incidence and multiplicity was observed 25 weeks after arresting treatment. An increase in NF-kappaB expression and binding activity, and under-expression of the inhibitor kappaB-alpha (IkappaB-alpha) were found in preneoplastic liver and neoplastic nodules, 5 and 25 weeks after initiation, respectively. These lesions also showed low expression of Mat1A and low activity of methionine adenosyltransferase I/III, whose reaction product, S-adenosyl-l-methionine, enhances IkappaB-alpha expression. SL-HPR prevented these changes and induced a decrease in expression of iNos, c-myc, cyclin D1 and Vegf-A genes, that were over-expressed in preneoplastic liver and nodules, and a decrease in Bcl-2/Bax, Bcl-2/Bad and Bcl-xL/Bax mRNA ratios with respect to the lesions of control rats. Liposomes alone did not influence the parameters tested. These results indicate that signal transduction pathways controlled by NF-kappaB, nitric oxide and S-adenosyl-l-methionine are deregulated in pre-cancerous lesions. Recovery from these alterations by SL-HPR is associated with chemoprevention of hepatocarcinogenesis. Overall, these studies elucidate some molecular changes, in early stages of hepatocarcinogenesis, and underline their pathogenetic role. Moreover, they demonstrate a partially new mechanism of HPR chemopreventive effect and indicate the potential clinical relevance of this compound for prevention of hepatocellular carcinoma.     

Knee arthrodesis with a press-fit modular intramedullary nail without bone-on-bone fusion after an infected revision TKA

IntroductionKnee arthrodesis can be an effective treatment after an infected revision Total Knee Arthroplasty (TKA). The main hypothesis of this study is that a two-stage arthrodesis of the knee using a press-fit, modular intramedullary nail and antibiotic loaded cement, to fill the residual gap between the bone surfaces, prevents an excessive limb shortening, providing satisfactory clinical and functional results even without direct bone-on-bone fusion.Material and methodsThe study included 22 patients who underwent knee arthrodesis between 2004 and 2009 because of recurrent infection following revision-TKA (R-TKA). Clinical and functional evaluations were performed using the Visual Analogue Scale (VAS) and the Lequesne Algofunctional Score. A postoperative clinical and radiographical evaluation of the residual limb-length discrepancy was conducted by three independent observers.ResultsVAS and LAS results showed a significant improvement with respect to the preoperative condition. The mean leg length discrepancy was less than 1 cm. There were three recurrent infections that needed further surgical treatment.DiscussionThis study demonstrated that reinfection after Revision of total knee Arthroplasty can be effectively treated with arthrodesis using a modular intramedullary nail, along with an antibiotic loaded cement spacer and that satisfactory results can be obtained without direct bone-on-bone fusion.     

Investigation of polyomaviruses replication in pediatric patients with nephropathy receiving rituximab

Rituximab is a chimeric monoclonal antibody reacting with the CD20 antigen on B cells. It has been proposed as treatment for the idiopathic nephrotic syndrome, recurrent idiopathic nephropathy, and focal segmental glomerulosclerosis refractory to steroids. Rituximab influences T-cell immunity and may predispose the patients to opportunistic infections, such as progressive multifocal leukoencephalopathy caused by the polyomavirus JC (JCV). The risk of latent viruses infections/reactivations in pediatric patients receiving monoclonal antibodies is not well known yet. In this longitudinal 6-month study, the effects of rituximab on JCV and BK virus (BKV) replication have been investigated. Blood, serum, and urine samples have been collected monthly from 11 pediatric patients (mean age: 11 years) with the idiopathic nephrotic syndrome and recurrent idiopathic nephropathy, under rituximab therapy. JCV and BKV real-time PCRs and sequencing of the viral protein 1 and the non-coding control region have been conducted. The same investigations have been undertaken on samples collected from eight pediatric patients (controls, mean age: 6 years), with idiopathic nephrotic syndrome or focal segmental glomerulosclerosis, treated with conventional chemotherapy. JCV was detected in the urine of one patient (9%), and one control (12.5%); BKV was found in the urine of 7/11 patients (63.6%) and 2/8 controls (25%) and in blood samples from four patients. No significant difference was found in the mean viral loads and in the viral molecular characterizations between the two groups. The polyomaviruses replication was not associated with rituximab therapy in children.     

Successful medical treatment of EBV smooth muscle tumor in a renal transplant recipient

Belingheri M, Comoli P, Locatelli F, Baldanti F, Martina V, Giani M, Ferraresso M, Cro L, Edefonti A, Ghio L. Successful medical treatment of EBV smooth muscle tumor in a renal transplant recipient.
Pediatr Transplantation 2010: 14:E101–E104. © 2009 John Wiley & Sons A/S. Abstract: EBV is associated with various malignancies in patients with acquired or induced immune impairment. EBV‐SMT is very uncommon in immunocompromised patients, and a kidney localization has been described only anecdotally. We report the case of a 17‐yr‐old kidney transplant recipient diagnosed as having an EBV‐SMT inside the renal graft, which was successfully managed by minimizing isolated immunosuppression.     

Initial fixation strength of a new hybrid technique for femoral ACL graft fixation: the bone wedge technique

Background Aperture fixation with interference screws matching the diameter of the tunnel is associated with the risk of graft laceration and graft rotation. Hypothesis A hybrid fixation technique (extracortical and aperture fixation) with undersized interference screw placed behind a bone wedge provides a higher fixation strength as aperture fixation with a screw alone matching the size of the tunnel. Study design Experimental laboratory study. Methods We evaluated the initial fixation strength (single cycle and cyclic loading tests) of hybrid and interference screw aperture fixation using different sized interference screws in porcine knees. Results Analysis of yield load, maximum load and stiffness in the single cycle loading test showed no statistically significant differences for hybrid fixation with a 1 mm undersized screw and aperture fixation with a screw matching the size of the tunnel. The use of an undersized screw alone resulted in low fixation strength. Conclusion The initial fixation strength of the hybrid technique with undersized screws is comparable to that of interference screw fixation matching the size. Clinical relevance The new “bone wedge fixation” is an alternative for ACL graft fixation without the risk of graft laceration and graft rotation.