Functions of heteromeric and homomeric isoamylase-type starch-debranching enzymes in developing maize endosperm.

Functions of isoamylase-type starch-debranching enzyme (ISA) proteins and complexes in maize (Zea mays) endosperm were characterized. Wild-type endosperm contained three high molecular mass ISA complexes resolved by gel permeation chromatography and native-polyacrylamide gel electrophoresis. Two complexes of approximately 400 kD contained both ISA1 and ISA2, and an approximately 300-kD complex contained ISA1 but not ISA2. Novel mutations of sugary1 (su1) and isa2, coding for ISA1 and ISA2, respectively, were used to develop one maize line with ISA1 homomer but lacking heteromeric ISA and a second line with one form of ISA1/ISA2 heteromer but no homomeric enzyme. The mutations were su1-P, which caused an amino acid substitution in ISA1, and isa2-339, which was caused by transposon insertion and conditioned loss of ISA2. In agreement with the protein compositions, all three ISA complexes were missing in an ISA1-null line, whereas only the two higher molecular mass forms were absent in the ISA2-null line. Both su1-P and isa2-339 conditioned near-normal starch characteristics, in contrast to ISA-null lines, indicating that either homomeric or heteromeric ISA is competent for starch biosynthesis. The homomer-only line had smaller, more numerous granules. Thus, a function of heteromeric ISA not compensated for by homomeric enzyme affects granule initiation or growth, which may explain evolutionary selection for ISA2. ISA1 was required for the accumulation of ISA2, which is regulated posttranscriptionally. Quantitative polymerase chain reaction showed that the ISA1 transcript level was elevated in tissues where starch is synthesized and low during starch degradation, whereas ISA2 transcript was relatively abundant during periods of either starch biosynthesis or catabolism.

Extracorporeal Cardiopulmonary Resuscitation for Management of Out-of-Hospital Cardiac Arrest in a Patient with Fulminant Myocarditis.

A 68-year-old male with a witnessed out-of-hospital cardiac arrest while jogging who was managed with extracorporeal cardiopulmonary resuscitation (ECPR) is presented. The patient was found to be in refractory ventricular fibrillation by emergency medical service personnel and underwent advanced cardiac life support (ACLS) protocol with placement of an automated chest compression device. He was emergently transported to the cardiac catheterization laboratory. Due to refractory ventricular fibrillation, he was placed on venoarterial extracorporeal membranous oxygenation (VA-ECMO). Coronary angiography at that time showed nonobstructive coronary artery disease. Management with VA-ECMO and other supportive measures were continued for 5 days, after which a cardiac magnetic resonance imaging was performed with findings consistent with acute myocarditis. His condition substantially improved, and he was discharged from the hospital with good neurologic and functional status. Fulminant myocarditis is often fatal, but aggressive supportive measures with novel ECPR protocols may result in recovery, as it happened in this case.

In vivo studies on the availability and toxicity of antisense oligonucleotides in bladder cancer.

BACKGROUND: The urinary bladder is an ideal organ for topical treatment. A substantial number of bladder cancer patients are resistant to conventional intravesical therapy. In search of new agents, antisense oligonucleotides (AS-ON) may be interesting candidates. The availability and toxicity as well as the effectivity of AS-ON after intravesical instillation in different rodent models were examined. MATERIALS AND METHODS: Acute toxicity of AS-ON was tested by intravenous application (215-1,000 mg/kg body weight (bw)) in NMRI mice (n=30). The uptake and distribution of isotope-labelled AS-ON in bladder tissue was determined in Sprague Dawley rats (n=12) by radioactivity after intravesical application (2.5 mg/kg bw 3H-labelled AS-ON). Additionally, uptake and effectivity studies of AS-ON in tumors were performed in MB-49 bladder cancer-bearing C57/B16 mice (n=6) by immunohistochemistry and fluorescence microscopy. RESULTS: No systematic side-effects were noticed after intravenous application of physiological doses of AS-ON in NMRI mice. The mortality rate was 20% at the highest dose of 1,000 mg/kg bw. The highest AS-ON availability after intravesical application in rats was noticed in the bladder wall (12.3 microg/g), while the systemic concentration was low (1.1 microg/g). In fluorescence microscopy analysis, AS-ON were detected in the outer cells of the bladder wall and around vessels. AS-ON accumulated in the cytoplasm and in the nuclei. Immunohistochemical analysis demonstrated a reduction of the Ki-67 positivity after treatment with AS-ON (43%) compared to the untreated controls (58%). CONCLUSION: These preclinical experiments have shown that intravesical antisense oligonucleotides are safe and accumulate in the bladder and in bladder tumors, whereas systemic concentrations remain low. These data are the basis of a first clinical phase I study with intravesical instillation of Ki-67 antisense oligonucleotides.

Results of secondary ureteral implantation after kidney transplantation.

BACKGROUND: We reviewed our experience with ureteral complications and secondary ureteral implantation after kidney transplantation. METHODS: Between 1997 and 2005, 636 patients underwent kidney transplantation at our transplant center. Ureteral implantation was performed in the Lich-Gregoire technique. Thirty-one patients with ureteral complications after kidney transplantation and subsequent secondary ureteral implantation were analyzed for operative parameters and long-term transplant function. RESULTS: Twenty-seven patients had a ureteral stenosis and 4 patients a ureteral leakage. In 25 patients (81%), a resection of the distal transplant ureter followed by secondary ureteral implantation was performed. In 4 cases (13%), the native ureter was anastomosed to the transplant pelvis and in the remaining 2 cases (6%) to the transplant ureter. Three major complications occurred. At median follow-up of 5 years, 18/30 patients (60%) had a good transplant function and 12/30 patients (40%) had returned to dialysis. One patient with depression died from suicide. CONCLUSIONS: Secondary ureteral implantation can be performed with acceptable morbidity and good long-term transplant outcome.