Characterization of chromosomal and membrane associated plasmid in Bacillus brevis ATCC 9999

A covalently closed circular (ccc) DNA, with a weight of 44.7 x 10(6) daltons, has been isolated from Bacillus brevis ATCC 999 (a gramicidin S producer) and from the gramicidin S-negative mutant EB16. The ccc DNA in the case of the parent strain, is mainly (99%) attached to the chromosome and membrane fraction. A restriction enzyme map of the plasmid DNA was constructed for the enzymes SalI, SmaI and BamHI, which cleaved the plasmid DNA into two, two and six fragments respectively. Further digestion with the endonucleases EcoRI and HindIII cleaved the plasmid into 17 and 22 fragments.     

Addition of nitrous oxide to fentanyl anesthesia does not induce myocardial ischemia in patients with ischemic heart disease

Although nitrous oxide is commonly administered to patients with ischemic heart disease, recent reports suggest that it may induce myocardial ischemia in these patients. The authors compared the effects of nitrous oxide on segmental left ventricular (LV) function and the ST segment of the electrocardiogram with the effects of an equal concentration of nitrogen (crossover design) before the start of surgery in 18 patients who required coronary-artery bypass grafting. The patients studied did not have valvular or LV dysfunction. Anesthesia was induced and maintained with intravenous fentanyl. After endotracheal intubation and 20 min of ventilation with 100% oxygen, either 60% nitrous oxide or 60% nitrogen (randomly assigned) was added to the inspired gas mixture of each patient for 10 min. This was followed by 10 min of 100% oxygen, and then 10 min of 60% nitrous oxide or 60% nitrogen, whichever had not been administered previously. Patients were monitored for myocardial ischemia using a standard 12-lead electrocardiogram and trans-esophageal two-dimensional echocardiography. Surgery did not begin until the study was concluded. No patient experienced an ST segment change greater than 1 mm during the study, and none developed a new segmental wall motion abnormality during inhalation of either nitrous oxide or nitrogen. The authors conclude that nitrous oxide does not induce myocardial ischemia when used as an adjunct to fentanyl anesthesia in patients who have severe coronary-artery disease accompanied by well-preserved valvular and LV function.     

Eosinophilia-myalgia syndrome after L-tryptophan intake

Since 1989 there has been an increasing number of reports on the association of L-tryptophan (LT) and eosinophilia-myalgia syndrome (EMS). It has now become evident that the clinical picture of EMS can vary. We report two further cases reflecting the clinical spectrum of the disease. The first patient had been taking LT for 8 years before the onset of myalgia. Subsequently, this patient developed an illness clinically and histologically resembling eosinophilic fasciitis. The second patient had been taking LT for 8 months before the onset of symptoms, which included myalgia, severe oedema of the lower extremities and induration of the skin involving arms, lower legs and abdomen. Discontinuation of LT and administration of oral steroids resulted in little improvement of the skin changes in the first patient. However, in the second patient skin involvement improved rapidly, whereas the neurological disorders have become more prominent.     

Narcotics decrease heart rate during inhalational anesthesia

We determined the heart rate (HR) response to enflurane, halothane, and isoflurane and the effects of narcotics on this response in 81 healthy patients scheduled for elective surgery. Patients were randomly assigned to one of six treatment groups: one of the three anesthetics (approximately 0.9 MAC) in 60% nitrous oxide, and either 0.15 mg/kg of intramuscular morphine 30-60 min before induction or 1 microgram/kg of IV fentanyl 10 min after skin incision. All patients received diazepam, 10 mg orally, 60-90 min before anesthesia, a rapid sequence intravenous induction, and mechanically controlled ventilation. During inhalational anesthesia and the first 10 min of surgery, no significant change in HR occurred in any group (compared to the preinduction HR), although patients given morphine premedication tended to have a decreased HR and those not given morphine premedication tended to have an increased HR. These trends partially account for significant differences that emerged between groups after induction of anesthesia. Patients given morphine premedication and halothane had lower HR (64 +/- 3 SEM) than patients given isoflurane (80 +/- 3) or enflurane (84 +/- 3) and no morphine premedication. Patients anesthetized with enflurane and morphine premedication had lower HR (71 +/- 3) than patients given enflurane without morphine premedication. Administration of fentanyl 10 min after incision (these patients had received no morphine) significantly decreased HR in the presence of any of the vapors. We conclude that inhalational anesthetics used in the clinical setting we employed do not significantly increase heart rate, and that prior administration of morphine or concurrent administration of fentanyl may significantly decrease HR.     

Intraoperative detection of myocardial ischemia in high-risk patients: electrocardiography versus two-dimensional transesophageal echocardiography

Because acute segmental wall motion abnormalities (SWMAs) of the left ventricle are highly sensitive and specific indicators of myocardial ischemia, this study compared the incidence and significance of ischemia, as detected by two-dimensional transesophageal echocardiography and surface electrocardiography, during anesthesia and surgery in patients at high risk of myocardial ischemia. During surgery, 24 of the 50 patients studied had new SWMAs, whereas only six had ST segment changes. All patients with ST segment changes also had new SWMAs: in three instances, SWMAs occurred before the ST segment change, and in three instances, they occurred simultaneously. All three patients who had intraoperative myocardial infarctions also had persistent intraoperative SWMAs, whereas only one patient had ST segment changes. Ten healthy patients requiring noncardiovascular surgery were monitored similarly; none of these had SWMAs, ST segment changes, or myocardial infarction. This study demonstrates the superiority of two-dimensional transesophageal echocardiography over electrocardiography for the intraoperative detection of myocardial ischemia. Furthermore, when new SWMAs persist to the conclusion of surgery, myocardial infarction is likely to have occurred.     

Cardiac tamponade complicating ventricular arrhythmia ablation: Real life data on incidence,management, and outcome

Background and Objective

Cardiac tamponade during ablation procedures is a life-threatening complication. While the incidence and management of tamponade in atrial fibrillation ablation have been extensively described, the data on tamponade during ventricular ablations are very limited. The purpose of this study is to shed light on the incidence, typical perforation sites, and optimal management as observed through real-life data in a tertiary referral center for ventricular ablation.

Methods and Results

Consecutive patients with structural heart disease undergoing ventricular tachycardia ablation from 2008–2020 were analyzed. Of the 1078 patients undergoing 1287 ventricular ablation procedures, 20 procedures (1.5%) were complicated by cardiac tamponade. In all but one patient, the tamponade was treated with emergent pericardial drainage, while nine patients eventually underwent surgical repair. The perforation occurred during transseptal or subxiphoid puncture in six patients, during ventricle mapping in two patients, and during ablation in five patients (predominantly basal left ventricle). Steam pop as definite perforation cause could only be established in two patients. Regardless of the management of the complication, all patients survived to discharge.

Conclusion

Cardiac tamponade during ventricular ablation occurred in 1.5% of the procedures. In nine patients cardiac repair was necessary. Perforation was mostly associated with subxiphoid puncture or ablation of the basal left ventricle.     

Geldanamycin activates a heat shock response and inhibits huntingtin aggregation in a cell culture model of Huntington's disease.

Huntington's disease (HD) is a progressive neurodegenerative disorder with no effective treatment. Geldanamycin is a benzoquinone ansamycin that binds to the heat shock protein Hsp90 and activates a heat shock response in mammalian cells. In this study, we show by using a filter retardation assay and immunofluorescence microscopy that treatment of mammalian cells with geldanamycin at nanomolar concentrations induces the expression of Hsp40, Hsp70 and Hsp90 and inhibits HD exon 1 protein aggregation in a dose-dependent manner. Similar results were obtained by overexpression of Hsp70 and Hsp40 in a separate cell culture model of HD. This is the first demonstration that huntingtin protein aggregation in cells can be suppressed by chemical compounds activating a specific heat shock response. These findings may provide the basis for the development of a novel pharmacotherapy for HD and related glutamine repeat disorders.     

Impact of Anesthesia Strategy and Valve Type on Clinical Outcomes After Transcatheter Aortic Valve Replacement

BackgroundThe randomized SOLVE-TAVI (compariSon of secOnd-generation seLf-expandable vs. balloon-expandable Valves and gEneral vs. local anesthesia in Transcatheter Aortic Valve Implantation) trial compared newer-generation self-expanding valves (SEV) and balloon-expandable valves (BEV) as well as local anesthesia with conscious sedation (CS) and general anesthesia (GA) in patients undergoing transfemoral transcatheter aortic valve replacement (TAVR). Both strategies showed similar outcomes at 30 days.ObjectivesThe purpose of this study was to compare clinical outcomes during 1-year follow-up in the randomized SOLVE-TAVI trial.MethodsUsing a 2 × 2 factorial design 447 intermediate- to high-risk patients with severe, symptomatic aortic stenosis were randomly assigned to transfemoral TAVR using either the SEV (Evolut R, Medtronic Inc., Minneapolis, Minnesota) or the BEV (Sapien 3, Edwards Lifesciences, Irvine, California) as well as CS or GA at 7 sites.ResultsIn the valve-comparison strategy, rates of the combined endpoint of all-cause mortality, stroke, moderate or severe paravalvular leakage, and permanent pacemaker implantation were similar between the BEV and SEV group (n = 84, 38.3% vs. n = 87, 40.4%; hazard ratio: 0.94; 95% confidence interval: 0.70 to 1.26; p = 0.66) at 1 year. Regarding the anesthesia comparison, the combined endpoint of all-cause mortality, stroke, myocardial infarction, and acute kidney injury occurred with similar rates in the GA and CS groups (n = 61, 25.7% vs. n = 54, 23.8%; hazard ratio: 1.09; 95% confidence interval: 0.76 to 1.57; p = 0.63).ConclusionsIn intermediate- to high-risk patients undergoing transfemoral TAVR, newer-generation SEV and BEV as well as CS and GA showed similar clinical outcomes at 1 year using a combined clinical endpoint. (SecOnd-generation seLf-expandable Versus Balloon-expandable Valves and gEneral Versus Local Anesthesia in TAVI [SOLVE-TAVI]; NCT02737150)