Charles Powell

Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase) was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis) and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtil...

In the early 90’s, it was discovered that a Plasma Focus (PF) system self-creates a plasma-target in which high energy-threshold nuclear-reactions occur at high reaction rates. Short life radioisotopes (SLR)s such as 13F, 17F, 15O, 14O, 13N have been generated (106–108 per pulse) with a PF-machine using 7 kJ energy storage to produce the plasmas. β− radioactivity from the SLRs is measured with rugged, Geiger counters inserted into the PF-chamber, and a specific SLR is identified by its half-life. The PF chamber (before discharge) is filled with a mixture of gases that constitutes the latter plasma-target-beam system, e.g., the elements required to produce specific SLRs through nuclear reactions. In this paper, arguments are presented showing that a modest sized PF-machine, using a 50–75 kJ fast capacitor-bank, when operated at pulse frequencies of 1–10 Hz can produce ≥ 109 SLRs/pulse. This paper reports the results of testing a PF as a breeder of SLRs with dual applications for: (i)...

The Asian citrus psyllid, Diaphorina citri, transmits a phloem-limited bacterium, Candidatus 'Liberibacter' asiaticus that causes citrus greening disease. Because juvenile hormone (JH) plays an important role in adult and nymphal development, we studied the final steps in JH biosynthesis in D. citri. A putative JH acid methyltransferase ortholog gene (jmtD) and its cognate cDNA were identified by searching D. citri genome database. Expression analysis shows expression in all life stages. In adults, it is expressed in the head-thorax, (containing the corpora allata), and the abdomen (containing ovaries and male accessory glands). A 3D protein model identified the catalytic groove with catalytically active amino acids and the S-adenosyl methionine (SAM)-binding loop. The cDNA was expressed in Escherichia coli cells and the purified enzyme showed high preference for farnesoic acid (FA) and homoFA (kcat of 0.752 × 10(-3) and 0.217 × 10(-3) s(-1), respectively) as compared to JH ...

Sugarcane is one of the most important crops cultivated for the production of sugar and ethanol. In our previous studies, an innovative positive selection system for obtaining transgenic sugarcane, which utilized the E. coli-derived manA gene as the selectable marker and mannose as the selective agent, was developed and patented in China. In this paper, the influence of phosphomannose isomerase (PMI) overexpression on the key enzymes of both glycolysis and sucrose metabolism was investigated in transgenic sugarcane through the manA gene. Overexpressed PMI increased hexokinase activity by approximately 24 % compared with non-transgenic control plants, but pyruvate kinase (PK) activity was reduced by approximately 14 %. In comparison with the non-transgenic control plants, the activities of sucrose synthase, sucrose-phosphate synthase, and acid invertase were also modestly affected in the PMI-overexpressing transgenic plants, but no significant differences were observed at the stalk e...

Endovascular aortic grafting represents a minimally invasive approach to aortic aneurysm repair. The technique requires a variety of new skills and extensive training. Telemedicine enhances mentoring and technical support for surgeons performing the technique.

Peripheral thrombolysis is an indispensible tool in the treatment of occlusive peripheral vascular disease (PVD). However, the use of intravascular thrombolytic agents carries a significant risk of morbidity and mortality. The aim of this study is to review a contemporary series of patients treated with catheter-directed thrombolytics in the treatment of occlusive PVD. A retrospective analysis was performed reviewing all patients who underwent catheter-directed thrombolytic therapy for PVD with recombinant tissue plasminogen activator (rt-PA) between 2005 and 2008. Data included clinical and demographic variables potentially associated with endpoints of technical success, hemorrhagic complications, and death. Data were analyzed with univariate and multivariate measures. Significance was assigned with p <0.05. Over the 36-month study, 125 thrombolytic procedures were performed. Indication for treatment was occlusive thrombus in native artery (49 cases, 37.6%), vein (13 cases, 10.4...

RNA interference (RNAi) is a powerful approach for elucidating gene functions in a variety of organisms, including mosquitoes and many other insects. Little has been done, however, to harness this approach in order to control adult and larval mosquitoes. Juvenile hormone (JH) plays a pivotal role in the control of reproduction in adults and metamorphism in larval mosquitoes. This report describes an approach to control Aedes aegypti using RNAi against JH acid methyl transferase (AeaJHAMT), the ultimate enzyme in the biosynthetic pathway of JH III that converts JH acid III (JHA III) into JH III. In female A. aegypti that were injected or fed jmtA dsRNA targeting the AeaJHAMT gene (jmtA) transcript, egg development was inhibited in 50% of the treated females. In mosquito larvae that were fed transgenic Pichia pastoris cells expressing long hair pin (LHP) RNA, adult eclosion was delayed by 3 weeks causing high mortality. Northern blot analyses and qPCR studies show that jmtA dsRNA caus...

Organic glasses can grow crystals much faster on the free surface than in the interior, a phenomenon important for fabricating stable amorphous materials. This surface process differs from and is faster than the glass-to-crystal (GC) growth mode existing in the bulk of molecular glasses. We report that similar to GC growth, surface crystal growth terminates if glasses are heated to gain fluidity. In their steady growth below the glass transition temperature Tg, surface crystals rise above the amorphous surface while spreading laterally and are surrounded by depressed grooves. Above Tg, the growth becomes slower, sometimes unstable. This damage is stronger on segregated needles (α indomethacin, nifedipine, and o-terphenyl) than on crystals growing in compact domains (γ indomethacin). This effect arises because the onset of liquid flow causes the wetting and embedding of upward-growing surface crystals. Segregated needles are at greater risk because their slow-growing flanks appear stationary relative to liquid flow at a low temperature. The disruption of surface crystal growth by fluidity supports the view that the process occurs by surface diffusion, not viscous flow. Compared to the bulk GC mode, surface crystal growth is disrupted less abruptly by fluidity. Nevertheless, to the extent that fluidity damages them, both processes are solid-state phenomena terminated in the liquid state.

Citrus huanglongbing (HLB), caused by three species of fastidious, phloem-limited 'Candidatus Liberibacter', is one of the most destructive diseases of citrus worldwide. To date, there is no established cure for this century-old and yet, newly emerging disease. As a potential control strategy for citrus HLB, 31 antibiotics were screened for effectiveness and phytotoxicity using the optimized graft-based screening system with 'Candidatus Liberibacter asiaticus' (Las)-infected citrus scions. Actidione and Oxytetracycline were the most phytotoxic to citrus with less than 10% of scions surviving and growing; therefore, this data was not used in additional analyses. Results of principal component (PCA) and hierarchical clustering analyses (HCA) demonstrated that 29 antibiotics were clustered into 3 groups: highly effective, partly effective, and not effective. In spite of different modes of actions, a number of antibiotics such as, Ampicillin, Carbenicillin, Penicillin, C...

A 44-year-old man with a type A dissection repair 5 years earlier presented with progressive enlargement of the residual arch and thoracic aorta. Flow into the false lumen from the distal aortic suture line was evident on contrast-enhanced computed tomography. Through a redo hemisternotomy, the false lumen was accessed directly. An Amplatzer plug was deployed within the narrowed neck of the false lumen proximal to the enlarged false lumen within descending aorta. Interlocking coils were deployed proximal to the Amplatzer plug, resulting in thrombosis of the false lumen.

Arteritis and mycotic aneurysms have been well described for more than 100 years. The authors report a case of bacterial arteritis that presented with pneumatosis of the aortic wall and that evolved over 1 week into an infected abdominal aortic aneurysm. This case documents the rapid progression from arteritis to mycotic aneurysm, highlighting the need for close radiologic follow-up and aggressive medical and surgical management.

Presented is a patient with an iatrogenic hepatic artery pseudoaneurysm that was treated by endovascular stent grafting. Endovascular stent grafting of a hepatic artery pseudoaneurysm offers a safe and potentially less morbid alternative to an open repair. The report stresses the necessity of careful preoperative evaluation with angiography to determine the feasibility of the procedure. An aggressive approach to treating hepatic artery pseudoaneurysms is advocated because of the poor correlation between size and their tendency to rupture. With an increasing rate of diagnosis of visceral artery aneurysms in elderly, debilitated patients, endovascular repair is anticipated to have an increasing role and should be considered a first-line therapy in anatomically suitable candidates.

To determine the role of total energy expenditure (TEE) and its components in the ability of collared lemmings to increase weight in response to a decrease in photoperiod. Energy expenditure was measured by 24-hour indirect calorimetry concurrent with food-intake studies. TEE and resting and nonresting energy expenditure (REE and NREE, respectively) were adjusted for body weight by analysis of covariance (ANCOVA). Uncoupling protein 1 (Ucp1) mRNA levels from interscapular brown adipose tissue were determined by Northern blot. TEE and REE of lemmings exposed to a short photoperiod for 10 days were significantly lower than that of lemmings exposed to a long photoperiod (p < 0.05), whereas NREE was not significantly different (p = 0.44). Ucp1 mRNA levels in interscapular brown adipose tissue were 50% lower in short- vs. long-photoperiod lemmings (p < 0.01). Ucp1 mRNA levels were positively related to REE (r2 = 0.79, p < 0.01). After adjustment of REE for differences in Ucp1 mRNA levels, there was no longer a significant difference attributable to photoperiod treatment (p = 0.54). The results of this study indicate that the increase in body mass that occurs when collared lemmings are exposed to a short photoperiod may be primarily fueled by a decrease in REE and is correlated with a decrease in Ucp1 mRNA levels.

Some radiotherapy patients are treated with titanium surgical aneurysm clips in the radiation field. This is of particular importance for stereotactic radiosurgery brain treatments, where the length of the blade of the clip may be comparable to the size of the radiation field. This study seeks to determine the extent of the dosimetric effects caused by surgical clips in stereotactic radiosurgery, using polyacrylamide gel phantoms and EBT type Gafchromic films. Using gel phantoms scanned with magnetic resonance imaging scanner, dose enhancement of around 20% was noted at distances less than 2 mm away from the clip surface. Gafchromic films showed about 6% variations in the dose up to few millimeters from the clip. These experimental results confirmed results predicted by Monte Carlo simulation techniques for higher density material surgical clips such as lead and platinum. Moreover, these experimental measurements clearly indicate dose reduction due to radiation attenuation behind the clip of about 4%.

Journal of Vascular Surgery, Volume 50, Issue 6, Pages 1545, December 2009, Authors:Christopher A. Durham; Michael M. McNally; Wesley T. O'Neal; Adam G. Strickland; Claudia E. Goettler; Curtis A. Anderson; Charles S. Powell; William M. Bogey; Frank M. Parker; ...

Traumatic aortic injury (TAI) is a rare yet highly lethal injury associated with blunt force deceleration injury. The adoption of thoracic endovascular aortic repair (TEVAR) has become a safer option than traditional open repair. The purpose of this study is to review a rural trauma center experience with TAI. A retrospective analysis was performed, reviewing all patients who presented with TAI between 2000 and 2009. Clinical, anatomical, and procedural variables of all cases were systematically reviewed. Clinical endpoints included mortality, and aortic-related mortality, and hospital length of stay. The study population was stratified by those that underwent surgical repair (SR) and those managed medically (MM). Fifty-six patients presented with blunt TAI; 35 patients (62.5%) were surgically repaired (22 open, 13 TEVAR), while 21 (37.5%) were MM. The only difference in comorbidities was a higher rate of coronary artery disease in MM. Mean hospital arrival time (SR, 188.6 ± 30.3 minutes, MM, 253 ± 65.3 minutes), aortic injury grade (SR, 2.7 ± 0.1; MM, 2.3 ± 0.2), and injury severity score were not significantly different between the groups. Head Abbreviated Injury Score (AIS) was worse in the MM group, while chest AIS was worse in the SR group (P < .05). There were nine (42.9%) deaths in the MM group, while there were only two (5.7%) in the SR group (P < .001). There was no significant difference in aortic-related mortality. Mean follow-up time was not statistically different. These data provide a group of stable patients to examine the management of TAI in the endovascular era. The low aortic-related mortality in the MM group demonstrates that there is time for a thorough evaluation in patients sustaining TAI who arrive without hemodynamic instability.

Within the context of healthcare system reform, the cost efficacy of lower extremity revascularization remains a timely topic. The impact of an individual patient's socioeconomic status represents an under-studied aspect of vascular care, especially with respect to longitudinal costs and outcomes. The purpose of this study is to examine the relationship between socioeconomic status and clinical outcomes as well as inpatient hospital costs. A retrospective femoropopliteal revascularization database, which included socioeconomic factors (household income, education level, and payor status), in addition to standard demographic, clinical, anatomical, and procedural variables were analyzed over a 3-year period. Patients were stratified by income level (low income [LI] <200% federal poverty level [$42,400 for a household of 4], and higher income [HI] >200% federal poverty level) and revascularization technique (open vs endovascular) and analyzed for the endpoints of primary assisted patency, amortized cost-per-day of patency, and limb salvage. Data were analyzed with univariate and multivariate techniques. A total of 187 cases were identified with complete data for analysis, 146 in the LI and 41 in the HI cohorts. LI patients differed from HI patients by mean age (66.2 +/- 1.0 vs 61.8 +/- 1.5 years, P = .04), high school graduate rate (51.4% vs 85.4%, P < .001), presence of tissue loss (30.1% vs 14.6%, P = .05), female gender (43.7% vs 22.0%, P = .01) and preoperative statin use (45.8% vs 75.6%, P < .001). There were no differences with respect to other comorbidities including smoking status, presence of diabetes, renal insufficiency, anatomic factors or treatment modality (open vs endovascular). Ninety-seven patients underwent endovascular revascularization. The following outcomes were noted in the endovascular subset of LI and HI patients respectively: primary assisted patency (66% vs 71%, P = NS) and 12-month cost-per-day of patency ($166.30 +/- 77.40 vs $22.45 +/- 12.45, P = .05). Ninety-eight patients underwent open revascularization, with the following outcomes in LI and HI patients respectively: primary assisted patency (78% vs 86%, P = NS) and 12-month cost-per-day of patency ($319.43 +/- 225.44 vs $40.47 +/- 4.63, P = .07). Of the 77 patients with critical limb ischemia, 19 underwent eventual amputation. Multivariate analysis demonstrated that income above 100% of the federal poverty line was protective against limb loss (odds ratio 0.06, 95% confidence interval 0.01-0.51, P < .001). Income level correlates with advanced presentation, advanced age, and lack of statin use. Although primary assisted patency rate is not affected by income status, an increased cost-per-day of patency and inferior limb salvage is found in lower income patients.

ABSTRACT Management of iatrogenic peripheral vascular injury has become of paramount importance because of the increasing incidence of this problem. Duplex ultrasonography is currently the method of choice for pseuodoaneurysm diagnosis. Traditional surgical repair has largely been replaced by less invasive techniques. Excellent results have been obtained with UGCR and USGTIR, with open surgical intervention currently reserved for selected indications. In comparison with UGCR and USGTIR, thrombin injection seems to be applicable in a higher percentage of patients. Use of the ultrasound-guided thrombin injection technique appears to save both time and resources. The success rate is equivalent to or better than that achieved with compression techniques, with lower recurrence rates. The procedure is well tolerated and the risks are minimal. USGTIR is the technique of choice for repair of iatrogenic false aneurysms in patients whom surgical repair is not indicated. More experience with USGTIR is necessary to confirm current success and complication rates.