Electron beam irradiation improves shelf lives of Korean ginseng (Panax ginseng C.A. Meyer) and red ginseng

Effect of electron beam irradiation on microbial growth and qualities of vacuum-packaged Korean ginseng and red ginseng during storage was investigated. Korean ginseng and red ginseng were treated at irradiation doses of 0, 2, 8, and 16 kGy. After treatment, samples were individually vacuum-packaged and stored at 20 degrees C. Microbial growth results of the irradiated samples presented that populations of total bacteria, yeast and mold, and total coliforms were decreased by 2 to 3 log CFU/g. The pH values of the samples were not significantly different among treatments. Thiobarbituric acid-reactive substance values of the samples increased during storage. Electron beam treatment caused negligible changes in Hunter's color L, a, and b values among the samples. Sensory evaluations like color and odor of the samples exhibited that there were no significant changes among the samples. During storage, content of saponin, a leading compound in ginseng, was not affected by irradiation. These results suggest that electron beam treatment should be useful in extending shelf lives of Korean ginseng and red ginseng.

Mechanisms in Experimental Venous Valve Failure and their Modification by Daflon© 500 mg

OBJECTIVES

To characterize the acute response of the vein wall to venous hypertension and associated altered fluid shear stress and to test the effect of micronized purified flavonoid fraction (MPFF, Daflon 500), on this response.

MATERIAL AND METHODS

A femoral arteriovenous fistula was created in Wistar rats (n=48). A cohort of 24 rats received oral treatment with MPFF (100 mg/kg/day body weight), 24 rats underwent the arteriovenous fistula procedure and received no treatment. At days 1, 7 and 21 the animals (n=8 at each time point) were killed. Experimental parameters measured included limb circumference, blood flow at the sapheno-femoral junction, leukocyte infiltration and gelatinase activity (matrix metalloproteinase, MMP).

RESULTS

The acute rise in venous hypertension was accompanied by limb edema and venous reflux together with an eventual loss of valve leaflets in the saphenous vein. There was an increase in granulocyte and macrophage infiltration into the venous wall and the surrounding tissue, and a lesser increase in T- and B-lymphocyte infiltration. These changes were accompanied by a local increase in the proteolytic enzymes, MMP-2 and MMP-9. Administration of MPFF reduced the edema and lessened the venous reflux produced by the acute arteriovenous fistula. Decreased levels of granulocyte and macrophage infiltration into the valves were also observed compared with untreated animals.

CONCLUSIONS

Venous hypertension caused by an arteriovenous fistula resulted in the development of venous reflux and an inflammatory reaction in venous valves culminating in their destruction. MPFF was able to delay the development of reflux and suppress damage to the valve structures in this rat model of venous hypertension.

Alemtuzumab plus CHOP as front-line chemotherapy for patients with peripheral T-cell lymphomas

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Background: The present study was conducted to evaluate the safety and efficacy of alemtuzumab plus CHOP chemotherapy for patients with peripheral T-cell lymphomas (PTCLs). Methods: Twenty patients with newly diagnosed PTCLs were enrolled. The treatment consisted of classical CHOP plus alemtuzumab (10 mg/m2 i.v on day 1 and 20 mg/m2 i.v on day 2 in the first cycle, then 30 mg/m2 i.v on day 1 in the subsequent cycles) based on 3-week intervals. Results: Thirteen complete responses (65.0%) and 3 partial responses (15.0%) were confirmed, giving an overall response rate of 80.0 %. The estimated event-free survival at 1 year was 43.3%. The most severe hematologic adverse event was neutropenia, which occurred with a grade 4 intensity in 18 patients (90.0%). Plus, febrile neutropenia was observed in 11 patients (55.0%). Five patients (25%) experienced CMV (cytomegalovirus) reactivation, while 3 patients developed CMV diseases, such as pneumonitis or retinitis. There were 2 treatment-related deaths. Conclusions: The alemtuzumab plus CHOP chemotherapy seemed to produce active antitumor activity in terms of the complete response rates in patients with PTCLs. However, since high infectious and hematologic toxicities were observed, careful monitoring and early treatment to prevent treatment-related mortality are needed.

No significant financial relationships to disclose.

Patients with irritable bowel syndrome or constipation have an increased risk for ischaemic colitis

AIMS

To estimate the relative risk for ischaemic colitis in patients with and without irritable bowel syndrome or constipation, and to evaluate the role of irritable bowel syndrome and constipation as confounders in the relationship between commonly used gastrointestinal medications and ischaemic colitis.

METHODS

Patient cohorts were identified with the use of longitudinal MarketScan research databases from 1 January 1999 to 31 December 2002. Patients in each study cohort were matched 1:1 with comparable control patients using a propensity score. A Cox proportional hazards models were used to estimate relative risk for ischaemic colitis.

RESULTS

The relative risk for ischaemic colitis was 3.17 and 2.78 times higher for patients with irritable bowel syndrome and constipation, respectively, than for those without these disorders. Patients who were taking an antispasmodic, a proton pump inhibitor, or an H2-antagonist were at increased risk for ischaemic colitis [relative risk with 95% CI 2.73 (1.41-5.39), 2.00 (1.05-3.79), 2.75 (1.22-6.17) respectively]; however, when these results were adjusted for irritable bowel syndrome or constipation, the relative risks were attenuated and no longer statistically significant.

CONCLUSIONS

Patients with irritable bowel syndrome or constipation demonstrated a two- to threefold increased risk for ischaemic colitis. Moreover, irritable bowel syndrome and constipation strongly confounded the relationship between gastrointestinal drug use and the risk for ischaemic colitis, suggesting that etiologic studies of ischaemic colitis risk must account for the presence of irritable bowel syndrome or constipation.

Review of Reservoir Parameters to Optimize SAGD and Fast-SAGD Operating Conditions

Abstract

Although high recovery efficiency is expected from the SAGD process, high steam production costs and the substantial volumes of water required have made us focus on more effective recovery methods. One such method is the Fast-SAGD process which utilizes one or more offset horizontal wells parallel to the original SAGD well pair.

In these studies, simulations were used to examine the reservoir parameters and operating conditions that need to be in place to optimize the SAGD process. Based on the simulation of a typical Cold Lake reservoir in Alberta, the studies found that relatively clean sand reservoirs with a minimum thickness of 20 m and a vertical permeability of 2.5 Darcy are good candidates for the application of SAGD. Also, reservoirs in a fining upward depositional environment are ideally suited for a SAGD operation.

The results of our studies also showed that, for the same operating conditions, Fast-SAGD improved energy efficiency by 24% and productivity by 35% over SAGD. Fast-SAGD is therefore a more efficient recovery process requiring less steam and having lower operating costs to produce the same amount of bitumen.

The case of two offset wells located on either side of one SAGD well pair promises the most effective Fast-SAGD configuration, even if a total of six offset wells with a SAGD well pair is still economic compared to the conventional SAGD process. Cumulative bitumen production is increased and at the same time the cumulative steam-oil ratio is decreased as a result of higher thermal efficiency.

Introduction

Alberta's oil sands contain the largest crude bitumen resource in the world, having approximately 259 billion cubic metres of initial oil in-place and 27.7 billion cubic metres of remaining established reserves (see Tables 1a and 1b)(1). Over 80% of these reserves can be produced only by using in situ recovery methods; therefore, research to find more effective in situ recovery methods is encouraged.

The SAGD process has been tested in the field, and is now in a commercial stage of production in Western Canadian oil sands(2). The application of SAGD in various reservoir conditions has been studied, and recently research studies that can not only reduce the steam production cost but also enhance heat efficiency of the SAGD process have been conducted(3).

In our studies, the characteristics of the SAGD recovery method were reviewed. In addition, the proper reservoir conditions and optimized operating conditions for the SAGD process were researched by conducting numerical simulation. The possibility of applying the Fast-SAGD process, a modification of the SAGD process(4), was also investigated in comparison to conventional SAGD. Finally, the operating conditions for the optimization of the Fast-SAGD process were studied.

Variations of SAGD Process

Enhancements

The conventional SAGD process is a steam injection recovery method which uses two horizontal wells. In the Peace River area, a small pressure differential between adjacent pattern steam chambers was applied to enhance the SAGD process(5). A steam drive process can be applied to the SAGD operation once sufficient bitumen mobility has been obtained between steam chambers.