Studies on the increased absorption of ouabain,phenolsulphonphthalein and pralidoxime caused by sodium lauryl sulphate from single loop preparations in the rat

Summary In concentrations above the critical micelle concentration (effective range about 2 mM to about 22 mM) sodium lauryl sulphate caused graded increases in the absorption of ouabain, phenolsulphonphthalein and pralidoxime from jejunal loops in anaesthetized rats. The surfactant-caused increases in the absorption of phenolsulphonphthalein and pralidoxime were significantly reduced if the sodium chloride of the medium was replaced by mannitol, respectively sucrose, or by sodium phosphate, and also if ouabain was added to the medium. The extent in absorption in the absence of surfactant was not altered. The surfactant-caused increase in the absorption of ouabain was not reduced by the mentioned sodium chloride exchanges in the medium. It is suggested that the increased absorption caused by sodium lauryl sulphate must be ascribed to a direct effect on the intestinal membrane. The results indicate some kind of Na-dependence for the increase in absorption observed for phenolsulphonphthalein and pralidoxime. Additional studies are in progress to further elucidate the observations mentioned.     

Stepwise occurrence of a complex unbalanced translocation in neuroblastoma leading to insertion of a telomere sequence and late chromosome 17q gain

In neuroblastoma, the most frequent genetic alterations are unbalanced translocations involving chromosome 17. To gain insights into these rearrangements, we have characterized a previously identified der(1)t(1;17) of the CLB-Bar cell line. The 17q breakpoint was mapped by FISH. Subsequently, a rearranged fragment was identified by Southern analysis, cloned in a lambda vector and sequenced. The chromosome rearrangement is more complex than expected due to the presence of an interstitial 4p telomeric sequence between chromosome 1p and 17q. Three different genes, which may play a role in neuroblastoma development, are disrupted by the translocation breakpoints. Indeed, the 3'UTR of the PIP5K2B gene on chromosome 17q is directly fused to the (TTAGGG)n repeat of the chromosome 4p telomere, and the (1;4) fusion disrupts the MACF1 (microtubule-actin crosslinking factor 1) and POLN genes, respectively. Interestingly, the (1;4) fusion was present at diagnosis and at relapse, whereas the (4;17) fusion was detected at relapse only, leading to a secondary 17q gain confirmed by array CGH therefore indicating that 17q gain may not be a primary event in neuroblastoma. Finally, screening of a panel of neuroblastoma cell lines identified interstitial telomeric sequences in three other cases, suggesting that this may be a recurrent mechanism leading to unbalanced translocations in neuroblastoma.     

Vascular targeting in pancreatic cancer: the novel tubulin-binding agent ZD6126 reveals antitumor activity in primary and metastatic tumor models

ZD6126 is a novel vascular-targeting agent that acts by disrupting the tubulin cytoskeleton of an immature tumor endothelium, leading to an occlusion of tumor blood vessels and a subsequent tumor necrosis. We wanted to evaluate ZD6126 in primary and metastatic tumor models of human pancreatic cancer. Nude mice were injected orthotopically with L3.6pl pancreatic cancer cells. In single and multiple dosing experiments, mice received ZD6126, gemcitabine, a combination of both agents, or no treatment. For the induction of metastatic diseases, additional groups of mice were injected with L3.6pl cells into the spleen. Twenty-four hours after a single-dose treatment, ZD6126 therapy led to an extensive central tumor necrosis, which was not seen after gemcitabine treatment. Multiple dosing of ZD6126 resulted in a significant growth inhibition of primary tumors and a marked reduction of spontaneous liver and lymph node metastases. Experimental metastatic diseases could be significantly controlled by a combination of ZD6126 and gemcitabine, as shown by a reduction of the number and size of established liver metastases. As shown by additional in vitro and in vivo experiments, possible mechanisms involve antivascular activities and subsequent antiproliferative and proapoptotic effects of ZD6126 on tumor cells, whereas direct activities against tumor cells seem unlikely. These data highlight the antitumor and antimetastatic effects of ZD6126 in human pancreatic cancer and reveal benefits of adding ZD6126 to standard gemcitabine therapy.     

Postoperative analgesia and functional recovery after total-knee replacement: comparison of a continuous posterior lumbar plexus (psoas compartment) block, a continuous femoral nerve block, and the combination of a continuous femoral and sciatic nerve block

BACKGROUND AND OBJECTIVES: Continuous femoral nerve block is a well-accepted technique for regional analgesia after total-knee replacement. However, many patients still experience considerable pain at the popliteal space and at the medial aspect of the knee. The goal of this study is to evaluate whether a psoas compartment catheter provides better postoperative analgesia than a femoral nerve catheter does and whether it is as effective as the combination of a femoral and a sciatic nerve catheter and, thus, improves functional outcome. METHODS: Ninety patients who underwent total-knee replacement under standardized general anesthesia participated in this prospective randomized study. Group FEM received a continuous femoral nerve block, group FEM/SCI received a combination of a femoral and a sciatic continuous nerve block, and group PSOAS received a continuous psoas compartment block. Patient-controlled analgesia with piritramide was available for 48 hours. Maximal bending and extending of the knee and walking distance was assessed during the first 7 days. A standardized telephone survey was conducted after 9 to 12 months to evaluate residual pain and functional outcome. RESULTS: Postoperative opioid consumption during 48 hours was significantly less in the FEM/SCI group (median: 18 mg; 25th/75th percentile: 6/40) compared with the FEM group (49 mg; 25/66) and the PSOAS group (44 mg; 30/62) (P =.002). Postoperative pain scores were not different, and no differences occurred with respect to short-term or long-term functional outcome. CONCLUSION: The FEM/SCI catheter is superior to FEM and PSOAS catheter with respect to reduced analgesic requirements after total-knee replacement, but functional outcome does not differ with those 3 continuous regional analgesia techniques.     

Immunophenotypic and genetic characterization of a CD8 positive mantle cell lymphoma in a patient with concomitant Mycosis fungoides

Mantle cell lymphoma (MCL) is immunophenotypically characterized by cell surface co-expression of CD19, CD20, CD5, IgM and FMC7. However, the concomitant presence of other antigens distinctive of a particular leukocyte subset, e.g. T-lymphocytes, is an exceptional finding in MCL. Here, the first case of a blastic MCL in leukaemic phase with aberrant expression of the T-cell associated antigen CD8 occurring in a patient with concomitant Mycosis fungoides is described. Comprehensive immunophenotypic analysis showed that the MCL cells expressed the typical B-lymphocytic markers, were CD5 and CD8 positive, but did not express other T-cell proteins, such as CD2, CD3, CD4, CD7, TCRalphabeta and TCRgammadelta. The MCL cells expressed both CD8alpha and CD8beta chains indicating cell surface presence of CD8alphabeta heterodimers. Intriguingly, expression of the cytotoxic enzymes perforin and granzyme A was detected by RT-PCR. Cytogenetic and molecular genetic analysis of the lymphoma cells confirmed cyclin D1 overexpression secondary to the t(11;14)(q13;32) chromosomal translocation. Furthermore, trisomy 11, trisomy 14 and extra copies of t(11;14) translocated chromosomes were detected in sub clones of the analyzed MCL cells. Clinically, an aggressive course of disease including cerebral lymphoma involvement was noted in the reported patient. Hence, systematic studies addressing the incidence, biology and clinical behavior of this form of MCL seem to be justified in future.     

Treatment of acquired hemophilia by the Bonn-Malmo Protocol: documentation of an in vivo immunomodulating concept

Acquired hemophilia (AH) is an extremely rare condition in which autoantibodies (inhibitors) against clotting factor VIII induce acute and life-threatening hemorrhagic diathesis because of abnormal blood clotting. The mortality rate of AH is as high as 16%, and current treatment options are associated with adverse side effects. We investigated a therapeutic approach for AH called the modified Bonn-Malmo Protocol (MBMP). The aims of MBMP include suppression of bleeding, permanent elimination of inhibitors, and development of immune tolerance, thereby avoiding long-term reliance on coagulation products. The protocol included immunoadsorption for inhibitor elimination, factor VIII substitution, intravenous immunoglobulin, and immunosuppression. Thirty-five high-titer patients with critical bleeding who underwent MBMP were evaluated. Bleeding was rapidly controlled during 1 or 2 apheresis sessions, and no subsequent bleeding episodes occurred. Inhibitor levels decreased to undetectable levels within a median of 3 days (95% confidence interval [95% CI], 2-4 days), factor substitution was stopped within a median of 12 days (95% CI, 11-17 days), and treatment was completed within a median of 14 days (95% CI, 12-17 days). Long-term follow-up (7 months-7 years) showed an overall response rate of 88% for complete remission (CR). When cancer patients were excluded, the CR rate was 97%.     

A Comparison of the Inhibition by Cardiac Glycosides of the Isolated Intestine from the Rat and the Guinea Pig

A method described by Bieltvedt & Briseid (1966) and Bieltvedt (1967) for the determination of the inhibition by cardiac glycosides of the isolated, histamine-stimulated guinea pig ileum was modified to estimate the inhibition of the acetylcholine-stimulated rat jejunum. The glycoside concentrations causing 50 % inhibition of submaximal, isotonic contractions were determined, and the procedure was based on 20-minute contact periods between the muscle preparations and the cardioactive substances, and then 22-minute equilibration periods with chemical stimulation. The degree of inhibition was found to depend on the potassium content of the Tyrode solutions used. In a low potassium Tyrode solution (1.8 mM) the inhibition of the rat intestine by cardiac glycosides was found to be of the same order of magnitude as the inhibition of the guinea pig intestine. When the potassium chloride concentration was increased to 2.7 mM, the well known species difference was observed, the concentration of cardiac glycoside required for inhibition of the rat intestine being about 30 times higher than that required for inhibition of the guinea pig intestine. The range of potency of the different cardiac glycosides and aglycones which were tested in the low potassium. Tyrode solution, was the same for the two species. Presupposing an inhibition of Na⁺, K⁺-activated transport ATPases as the basic mechanism for the inhibition by cardiac glycosides of the isolated intestine preparations, a theory of qualitative differences between the transport enzymes in the two species is advanced. In the rat intestine the presence is suggested of one ATPase which is rather resistant to inhibition by cardiac glycosides, but sensitive to a reduction in potassium concentration, in addition to a glycoside-susceptible ATPase also present in the guinea pig intestine.     

Changes of protein synthesis in the hypertrophying rat heart

Summary Myocardial protein synthesis was studied in rats in vivo during the first five days of the development of cardiac hypertrophy induced by aortic constriction. Using l-¹⁴C-glycine or l-¹⁴C-leucine as precursor amino acids, rates of protein synthesis were determined from the total radioactivity of proteins and the mean radioactivity of the intracellular amino acid precursor pool and the leucine pool, respectively. During the first 5 h after aortic constriction the radioactivity of proteins did not change remarkably, whereas the radioactivity of the amino acid precursor pool was significantly elevated. Myocardial protein synthesis proved therefore to be diminished in this initial phase. After 24 h protein synthesis reached the range of sham-operated controls and thereafter increased almost parallel with the elevation of the ratio heart weight/body weight. The inhibition of protein synthesis was accompanied by a moderate decrease of ATP and creatine phosphate levels. A diminution of the high energy phosphate compounds, a decreased RNA synthesis or the action of inhibitory metabolites are considered possible factors involved in the decline of protein synthesis during the early phase of cardiac hypertrophy.Preliminary reports of this investigation were presented at the 36th Meeting of the German Physiological Society, Mainz, September 1969 [42] and at the XXV International Congress of Physiological Sciences, Munich, July 1971 [43].Supported by a grant from the Deutsche Forschungsgemeinschaft (Ge 129/7,8).