Enhancing the stability of a carboxylesterase by entrapment in chitosan coated alginate beads.

A carboxylesterase isolated from Aeromonas caviae MTCC 7725 was immobilized by entrapping it in chitosan coated calcium alginate beads. This was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The activity of the native and immobilized enzyme was measured at various temperatures, pH levels, and organic solvents. The optimum temperature for activity of the native enzyme was found to be 40 °C and this increased to 50 °C on immobilization. The immobilized enzyme showed enhanced stability and high residual activity in various organic solvents as compared to the free enzyme. An environmentally benign approach was used for the synthesis of ethyl salicylate using the immobilized enzyme. The product obtained was confirmed by GC-MS. The kinetic parameters, such as K m and Vmax, were also determined for the native and immobilized enzyme. The immobilized enzyme retained 50% of its activity after vfie cycles. The immobilized enzyme retained 80% and 40% of its activity at 4 °C and at 37 °C, respectively, at the end of 40 days. The results obtained from our study show that the immobilized enzyme can serve as a robust catalyst for industrial applications.

Endovascular treatment for thoracoabdominal aneurysms: outcomes and results.

OBJECTIVE: Endovascular treatment of thoracoabdominal aortic aneurysms (TAAA) in combination with selective open surgical revascularization may be an alternative to conventional surgical repair. We analyzed our patient outcomes after elective and emergent endovascular TAAA repair. METHODS: Mortality and outcome data from 21 consecutive patients treated with endovascular TAAA repair between 2000 and 2006 were reviewed. An integrated neuroprotective approach was used on all patients. Mortality risk estimates for open surgery (OS) were calculated using the published risk assessment models and compared to our outcomes. RESULTS: Of the 21 patients, 9 had acute presentation: acute pain (9), rupture (6), and malperfusion (1). The celiac axis was overstented in 15. Nine hybrid open surgical procedures were performed: visceral/renal arteries (5), infrarenal aorta (3) and complete arch revascularization (1). Eleven patients had previous aortic surgery. Thirty-day mortality rate was 4.8% (1/21, predicted OS value 8.3%), 1-, 2- and 3-year survival was 80%. One hospital death occurred due to ischemic colitis after inferior mesenteric artery overstenting. No patient with acute presentation died during the initial hospital admission. There was no paraplegia (predicted OS rate 11.46%) and one event of delayed temporary paraparesis 3 weeks after hospital discharge corrected with raising the blood pressure. Other neurologic complications included one minor left pontine stroke with complete resolution, postoperative confusion (1) and saphenous nerve injury (1). No new late endoleaks occurred after initial complete aneurysm exclusion. Five patients underwent early (<30 days) and four patients underwent late endovascular reinterventions for persistent endoleak. An additional reintervention included percutaneous stenting of a superior mesenteric artery stenosis. Actual freedom from late reintervention was 81%, and 76% at 1-, 2 and 3-year follow-up. Late major adverse events included one stent infection leading to multi-organ failure and death. CONCLUSIONS: Endovascular treatment of thoracoabdominal aneurysms with selective visceral and renal revascularization is associated with low mortality and can only be effectively performed by a surgeon. High-risk patients and those with acute presentation appear to benefit most from this therapy. Early results up to three years of this therapy are encouraging, but further follow up to validate long-term results is required.

Structured electronic documentation (SED) cardiac surgery and PowerNote- a pilot project.

User Specific templates were created through Cerner PowerNote to fit the need for improving the turnaround time for the Operative notes for Cardiac Surgery Patients. This eliminated the lag time of 37.5hours for Intensive Care Unit staff to access the detailed Operative notes on Cardiac surgery patients.

Endobronchial metallic stent placement for airway complications after lung transplantation: longitudinal results.

BACKGROUND: In lung transplant recipients, bronchial stenosis (SB) and bronchomalacia (MB) result in obstructive airway disease and allograft dysfunction due to pulmonary infection. We hypothesized that endobronchial metallic stent placement for SB and MB would result in long-term improvement in respiratory function and rates of pulmonary infection. METHODS: We studied symptomatic lung transplant recipients with bronchoscopic evidence of proximal airway complications (SB or MB) and a synchronous decline in forced expiratory volume in 1 second (FEV1) of at least 10% in the 6-month period before intervention. Stent placement was the primary intervention for SB and all focal MB lesions and for recurrent or refractory SB lesions failing a single initial attempt at balloon dilation. FEV1 and rates of pulmonary infection were assessed in the 12-month interval before and after stent placement. Spirometric evaluation was performed at 3-month intervals and compared with spirometry at the time of stent placement. The rates of pulmonary infection, determined by the number of antibiotics prescribed, was determined before and after endobronchial correction. RESULTS: Thirty recipients underwent a total of 75 procedures (50 stent insertions and 25 balloon dilations). FEV1 improved significantly after stent placement compared with base line (1.29 +/- 0.43 L) as follows: 3 months, 1.45 +/- 0.50 L, p = 0.014; 6 months, 1.59 +/- 0.57 L, p = 0.002; 12 months 1.59 +/- 0.53 L, p = 0.006. The infection rate decreased from the 12-month period preceding stent insertion to the corresponding period after stent insertion (6.97/100 days +/- 6.33 versus 5.74/100 days +/- 7.76, p = 0.018). Recurrent SB occurred in 17.3%. No life-threatening complications occurred after stent placement and no deaths were attributed to stent malfunction or malposition. CONCLUSIONS: In lung transplant recipients with SB and MB, maintenance of airway patency by stent placement is safe and resulted in improvements in lung function and reduced pulmonary infection rates for up to 1 year after their insertion.