Objective Outcomes of open revascularization (OR) and endovascular revascularization (ER) for chronic mesenteric ischemia (CMI) were analyzed to identify predictors of endovascular failure. Methods A ...retrospective study was performed of all consecutive patients with CMI (161 patients, 215 vessels) treated from 2008 to 2012. Demographics, comorbidities, clinical presentation, etiology, and treatment modalities were compared. Outcomes included technical success, restenosis requiring reintervention, complications, mortality, and hospital length of stay. Results There were 116 patients who were first treated with ER (72%) and 45 patients with OR (28%). Overall mortality was 6.8% (11/161). Among the ER patients, 27 developed restenosis and required OR (23%). Patients treated with ER were older (73 vs 66 years; P = .014), had similar comorbidities, and had higher rate of short lesions (≤2 cm) on preoperative angiograms (23% vs 47%; P = .004). Primary patency at 3 years was higher in the OR group compared with the ER group (91% vs 74%; P = .018). Long-term survival rates were higher in the ER group (95% vs 78%; P = .003). Hospital length of stay and intensive care unit length of stay were shorter in the ER group (<.001). Perioperative mortality (30-day) was not statistically significant between the groups (5.2% vs 11%; P = .165). A subgroup analysis was performed between the patients with successful ER and failure of ER requiring OR. Patients with failure of ER had significantly higher rates of aortic occlusive disease (86% vs 49%; P = .005) and long lesions ≥2 cm on angiography (57% vs 12%; P < .001) that were close to the mesenteric takeoff. Perioperative mortality was higher in the ER failure group (15% vs 2%; P = .009). Conclusions ER has similar perioperative mortality and shorter hospitalization but higher rate of restenosis requiring reintervention compared with OR. Patients with ER who required reintervention appear to have longer lesions as well as higher rates of aortic occlusive disease on preoperative angiography. Patients who crossed over from ER to OR had higher perioperative mortality than either primary open or endovascular patients. These findings may guide treatment selection in patients with CMI undergoing ER or OR.
To describe the fluidic events that occur in a test chamber during phacoemulsification with longitudinal and torsional ultrasound (US) modalities.
Pasteur Ophthalmic Clinic Phacodynamics Laboratory, ...Santiago, Chile, and Nanyang Technological University, Singapore.
Experimental study.
Ultra-high-speed videos of a phacoemulsifying tip were recorded while the tip operated in longitudinal and torsional US modalities using variable US power. Two high-speed video cameras were used to record videos up to 625,000 frames per second. A high-intensity spotlight source was used for illumination to engage shadowgraphy techniques. Particle image velocimetry was used to evaluate fluidic patterns while a hyperbaric environmental system allowed the evaluation of cavitation effects. Tip-to-tissue interaction at high speed was evaluated using human cataract fragments.
Particle imaging velocimetry showed the following flow patterns for longitudinal and torsional modes at high US powers: forward-directed streaming with longitudinal mode and backward-directed streaming with torsional mode. The ultrasound power threshold for the appearance of cavitation was 60% for longitudinal mode and 80% for torsional mode. Cavitation was suppressed with pressure of 1.0 bar for longitudinal mode and 0.3 bar for torsional mode. Generation of previously unseen stable gaseous microbubbles was noted. Tip-to-tissue interaction analysis showed the presence of cavitation bubbles close to the site of fragmentation with no apparent effect on cutting.
High-speed imaging and particle image velocimetry yielded a better understanding and differentiated the fluidic pattern behavior between longitudinal and torsional US during phacoemulsification. These recordings also showed more detailed aspects of cavitation that clarified its role in lens material cutting for both modalities.
The regulation of the synthesis of ribosomal RNA is a key problem for the understanding of bacterial growth. Many different regulatory mechanisms involving cis and trans acting components participate ...in a concerted way to achieve the very efficient, flexible and coordinated production of this class of molecules. We have studied three different sequence regions within a ribosomal RNA transcription unit which are believed to control different stages of ribosomal RNA expression. In the first part of the study the function of AT-rich sequences upstream of the -35 hexamer of rRNA promoter P1 in the activation of rRNA transcription was analyzed. We confirm that a sequence dependent bend upstream of P1 is responsible for the high promoter activity. Experiments employing linker scanning mutations demonstrated that the distance as well as the angular orientation of the bent DNA is crucial for the degree of activation. In addition, the effect of the trans activating protein Fis on the transcription initiation of promoter P1 was investigated. We can show, using the abortive initiation assay, that the predominant effect of Fis is due to an increase in the affinity of RNA polymerase for the promoter (binding constant KB) while the isomerisation rate (kf) from a closed to an open RNA polymerase promoter complex is not altered significantly. We also describe the characterization of sequence determinants important for stringent regulation and growth rate control. Evidence is provided that the discriminator motif GCGC is a necessary but not sufficient element for both types of control. Furthermore we show that not simply a particular DNA primary structure but the higher order conformation of the complete promoter region is recognized and triggers the two regulatory mechanisms, both of which are apparently mediated by the effector molecule guanosine tetraphosphate (ppGpp). Finally, we have carried out a systematic mutational analysis of the rrnB leader region preceding the structural gene for 16S RNA. We could demonstrate that highly conserved sequence elements within the rrnB leader, which were believed to be involved in transcription antitermination have post-transcriptional functions. We present evidence that these sequence elements direct the biogenesis of active ribosomal particles.
Methods A 5-question survey was given to a cohort of asthmatics to assess their perception of their weight, its role in their asthma control, and their willingness to pursue weight loss.
Twenty-five fit patients undergoing third molar surgery received the non-steroidal anti-inflammatory drug tenoxicam 40 mg given orally the night before surgery or intravenously at the time of surgery ...in a randomised, double-blind, cross-over trial. Propofol was used for intravenous sedation. Pain on injection was noted with propofol in 32-56 percent of subjects, but was mostly of minor nature. There was high (100 percent) acceptance of the method of sedation, with 60-84 percent rate of amnesia. Experience of post-operative pain, intake of medication, and trismus were similar with both methods of administration of tenoxicam. We conclude that both oral and intravenous administration of 40 mg tenoxicam are equally effective in healthy young patients undergoing third molar surgery.
A cluster analysis was performed using the following parameters: blood eosinophil level, total serum IgE, number of aeroallergen sensitivities (skin prick testing or serum ImmunoCAP to 18 relevant ...aeroallergens), spirometry, daily inhaled corticosteroid (ICS) dose, number of controller medications, age, BMI, and gender.
Methods After IRB approval, saliva was collected from asthmatics (n=26) and miRNAs were isolated by guanidium hydrochloride/phenol-chloroform extraction, reversed transcribed using a poly-A, ...3'adapter system, and analyzed by quantitative real-time PCR.
Background Increasing the number of arterial grafts for coronary artery bypass grafting (CABG) has been linked to improved late survival. Currently, it is not known if these long-term benefits are ...also true when sequential radial artery (RA) grafts are the primary means to maximizing arterial revascularization. Methods We compared late survival of 532 consecutive patients receiving sequential RA grafts (sequential RA group: 438 men; 462 with three-vessel disease) with that of a 4,131 contemporaneous internal thoracic artery (ITA) with saphenous vein (SV) multivessel CABG cohort (conventional group). Graft failure rates were determined from symptom-driven repeat angiography films in 122 sequential RA patients performed 2 to 4,317 days after surgery. Median survival sequential RA follow-up was 5.3 years (range, 0.5 to 12.3). Results The sequential RA patients received a total of 1,181 RA grafts (538 sequential 30 triple and 75 single) along with 636 SV and 533 ITA. Overall RA graft failure (80 of 272; 29%) was intermediate to that for ITA (7 of 121; 5.8%; p < 0.001) and vein (54 of 133, 41.6%; p = 0.032) grafts. Sequential versus nonsequential RA failure did not differ (77 of 252 31% versus 3 of 20 15%; p = 0.202), while failure of the proximal (36 of 123; 29%) and distal (40 of 129; 31%) components of sequential RA grafts were essentially identical. A total of 69 deaths (6 operative; 1.1%) have occurred in the sequential RA cohort. Unadjusted 10-year sequential RA cohort survival was 76.2% overall, and 79.0% for the 454 primary isolated CABG subgroup. The risk-adjusted 10-year survival using a logit propensity score was substantially better for the sequential RA cohort versus the conventional CABG cohort (risk ratio 95% confidence interval 0.61 0.44 to 0.85; p = 0.003). Conclusions Sequential RA grafting is a safe method for maximizing arterial revascularization and is associated with excellent 10-year survival that seems to be superior to conventional or ITA/SV CABG results. Also, the similar proximal and distal sequential RA patency mitigates concerns of a clinically significant effect of increased vasoreactivity of distal segments of RA conduits.
Transcription of ribosomal RNAs in Escherichia coli is started from two strong tandem promoters, P1 and P2. It is known, however, that internal promoter-like structures occur and in a recent report ...(Mankin et al., 1987) a promoter sequence Pi within the 16S and 23S RNA spacer region showing good homology to the prokaryotic consensus promoter structure was identified. It was proposed that this putative promoter has a possible function in the transcription of ribosomal RNAs in E. coli. Fusion of various DNA fragments containing the putative promoter sequence and different parts of the 16S/23S spacer region as well as the 23S RNA to the galactokinase gene allowed us to assess the functional activity of the promoter in vivo. To determine any growth rate dependent function of the putative promoter, the measurements were performed under different growth conditions. The promoter activity did not exceed 7% of the lac promoter under in vivo assay conditions. In addition, transcription starting at the promoter Pi did not proceed through the entire 23S RNA gene. We conclude, therefore, that transcription from Pi does not contribute significantly to the synthesis of ribosomal RNAs. Thus its functional significance, if any, remains elusive.
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