ABSTRACT
Esophago-pulmonary fistula after esophagectomy is a fatal complication of severe respiratory distress. Minimally invasive treatments, such as esophageal stent placement, have been developed to treat esophago-pulmonary fistulae; however refractory fistulae may not be cured by this mode of treatment. We encountered a case in which the esophago-pulmonary fistula did not close even though sealing of polyglycolic acid sheets and fibrin glue was administered three times over 4 mo while the esophageal stent was in place. We successfully closed this refractory esophago-pulmonary fistula using a vascular embolization plug under endoscopy. Our procedure can thus be an effective and less invasive treatment for refractory esophago-pulmonary fistula after esophagectomy.
Subject(s)
Esophageal Fistula , Esophageal Neoplasms , Humans , Esophagectomy/adverse effects , Esophageal Fistula/etiology , Esophageal Fistula/surgery , Endoscopy, Gastrointestinal , Stents/adverse effects , Esophageal Neoplasms/surgery , Esophageal Neoplasms/complicationsABSTRACT
Thermophilic proteins maintain their structure at high temperatures through a combination of various factors. Here, we report the ligand-induced stabilization of a thermophilic Ser/Thr protein kinase. Thermus thermophilus TpkD unfolds completely at 55 °C despite the optimum growth temperature of 75 °C. Unexpectedly, we found that the TpkD structure is drastically stabilized by its natural ligands ATP and ADP, as evidenced by the increase in the melting temperature to 80 °C. Such a striking effect of a substrate on thermostability has not been reported for other protein kinases. Conformational changes upon ATP binding were observed in fluorescence quenching and limited proteolysis experiments. Urea denaturation of Trp mutants suggested that ATP binding affects not only the ATP-binding site, but also the remote regions. Our findings shed light on thermoadaptation of thermophilic proteins.
Subject(s)
Mutation , Protein Serine-Threonine Kinases/chemistry , Protein Serine-Threonine Kinases/metabolism , Thermus thermophilus/enzymology , Adenosine Triphosphate/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Circular Dichroism , Enzyme Stability , Ligands , Protein Binding , Protein Serine-Threonine Kinases/genetics , Protein Structure, Tertiary , Proteolysis , Thermus thermophilus/genetics , Transition TemperatureABSTRACT
We have developed a temperature cycler for polymerase chain reaction (PCR) in a microwell fabricated on a polymer/glass chip. The entire system consisted of three subsystems, which included (1) a thermal conditioner, (2) a proportional-integral-derivative (PID) control signal conditioner and (3) a data acquisition subsystem. The subsystems were regulated coordinately by a ladder logic program written for the programmable logic control (PLC) so that an actual sample temperature could be timed, changed and maintained according to the programmed temperature cycles. The present temperature control system showed high accuracy, stability and minimum overshoot with reduced heating and cooling transition rates. Applicability of the temperature controller to the miniaturized PCR system with reduced volumes of aqueous sample droplets isolated in an oil phase was confirmed by successful amplifications of a target DNA sequence in the microwell.
Subject(s)
Miniaturization , Reverse Transcriptase Polymerase Chain Reaction/instrumentation , Temperature , Base Sequence , DNA Primers , Oils , Reproducibility of Results , WaterABSTRACT
The Hawaiian-Emperor hotspot track has a prominent bend, which has served as the basis for the theory that the Hawaiian hotspot, fixed in the deep mantle, traced a change in plate motion. However, paleomagnetic and radiometric age data from samples recovered by ocean drilling define an age-progressive paleolatitude history, indicating that the Emperor Seamount trend was principally formed by the rapid motion (over 40 millimeters per year) of the Hawaiian hotspot plume during Late Cretaceous to early-Tertiary times (81 to 47 million years ago). Evidence for motion of the Hawaiian plume affects models of mantle convection and plate tectonics, changing our understanding of terrestrial dynamics.
