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ABSTRACT: Abstract
Non-prescriptional use of medicinal herbs among cancer patients is common around the world. The alleged anti-cancer effects of most herbal extracts are mainly based on studies derived from in vitro or in vivo animal experiments. The current information suggests that these herbal extracts exert their biological effect either through cytotoxic or immunomodulatory mechanisms. One of the active compounds responsible for the immune effects of herbal products is in the form of complex polysaccharides known as β-glucans. β-glucans are ubiquitously found in both bacterial or fungal cell walls and have been implicated in the initiation of anti-microbial immune response. Based on in vitro studies, β-glucans act on several immune receptors including Dectin-1, complement receptor (CR3) and TLR-2/6 and trigger a group of immune cells including macrophages, neutrophils, monocytes, natural killer cells and dendritic cells. As a consequence, both innate and adaptive response can be modulated by β-glucans and they can also enhance opsonic and non-opsonic phagocytosis. In animal studies, after oral administration, the specific backbone 1→3 linear β-glycosidic chain of β-glucans cannot be digested. Most β-glucans enter the proximal small intestine and some are captured by the macrophages. They are internalized and fragmented within the cells, then transported by the macrophages to the marrow and endothelial reticular system. The small β-glucans fragments are eventually released by the macrophages and taken up by other immune cells leading to various immune responses. However, β-glucans of different sizes and branching patterns may have significantly variable immune potency. Careful selection of appropriate β-glucans is essential if we wish to investigate the effects of β-glucans clinically. So far, no good quality clinical trial data is available on assessing the effectiveness of purified β-glucans among cancer patients. Future effort should direct at performing well-designed clinical trials to verify the actual clinical efficacy of β-glucans or β-glucans containing compounds.
Journal of Hematology & Oncology. 01/2009;
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ABSTRACT: This study assessed midterm results of emergency endovascular stent-grafting for patients with life-threatening complications of acute type B aortic dissection.
Between November 1996 and June 2004, 16 patients with complicated acute type B aortic dissections (mean age 57 years, range 16-88 years) underwent endovascular stent-grafting within 48 hours of presentation. Complications included contained rupture, hemothorax, refractory chest pain, and severe visceral or lower limb ischemia. Stent-graft types included custom-made first-generation endografts and second-generation commercial stent-grafts (Gore Excluder or TAG; W. L. Gore & Associates, Inc, Flagstaff, Ariz.). Follow-up was 100% complete, averaged 36 +/- 36 months, and included postprocedural surveillance computed tomographic scans.
Early mortality was 25% +/- 11% (70% confidence limit), with no late deaths. No new neurologic complications occurred. According to the latest scan, 4 patients (25%) had complete thrombosis of the false lumen; the lumen was partially thrombosed in 6 patients (38%). Distal aortic diameter was increased in only 1 patient. Actuarial survival at 1 and 5 years was 73% +/- 11%; freedom from treatment failure (including aortic rupture, device fault, reintervention, aortic death, or sudden, unexplained late death) was 67% +/- 14% at 5 years.
With follow-up to 9 years, endovascular stent-grafting for patients with complicated acute type B aortic dissection conferred benefit. Consideration of emergency stent-grafting may improve the dismal outlook for these patients; future refinements in stent-graft design and technology and earlier diagnosis and intervention should be associated with improved results.
The Journal of thoracic and cardiovascular surgery 08/2008; 136(2):424-30. · 3.41 Impact Factor
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ABSTRACT: Effective learning in higher education is associated with students' perceptions of clear goals and standards of an educational program. In programs using problem-based learning (PBL), students' conceptions of what PBL is about could determine how well they perceive the clarity of goals and standards of their program. In this study the authors aim to investigate the relationship between the nature of first-year students' conceptions of PBL and their perceptions of the clarity of goals and standards of a graduate-entry, problem-based medical program. Results are that most students conceive of PBL as mainly working collaboratively to solve and understand a problem, and place less emphasis on PBL as learning independently. There is no relationship between students' conceptions and perceived clarity of course goals and standards. It is suggested that teachers not only need to help students develop their understanding of what PBL is about but also need to help students learn how to self-regulate their learning in PBL programs.
Medical Teacher 10/2006; 28(6):573-5. · 1.22 Impact Factor
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ABSTRACT: High-flow priapism results from disruption of the intercavernosal artery resulting in an arteriocavernosal fistula and is rarely encountered in the pediatric and adolescent population. Clinically it manifests as a painless, prolonged erection after perineal trauma. Treatment has ranged from expectant management to open surgical exploration with vessel ligation. Internal pudendal arteriogram and superselective embolization with autologous blood clot has emerged as a safe and effective treatment modality in the young male population. Here the authors present 3 patients with high-flow priapism and discuss management of this rare clinical entity.
Journal of Pediatric Surgery 05/2005; 40(4):E25-8. · 1.45 Impact Factor
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Journal of Thoracic and Cardiovascular Surgery 07/2004; 127(6):1808-10. · 3.41 Impact Factor
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ABSTRACT: Five years after reporting our initial stent-graft repair of descending thoracic aortic aneurysms experience, we determined the 5- to 10-year results of stent-graft treatment and identified risk factors for adverse late outcomes.
Between 1992 and 1997, 103 patients (mean age 69 +/- 12 years) underwent repair using first-generation (custom-fabricated) stent grafts. Sixty-two patients (60%) were unsuitable candidates for conventional open surgical repair ("inoperable"). Follow-up was 100% complete (mean 4.5 +/- 2.5 years; maximum 10 years). Outcome variables included death and treatment failure (endoleak, aortic rupture, reintervention, and/or aortic-related or sudden death).
Overall actuarial survival was 82% +/- 4%, 49% +/- 5%, and 27% +/- 6% at 1, 5, and 8 years. Survival in open surgical candidates was 93% +/- 4% and 78% +/- 6% and at 1 and 5 years compared with 74% +/- 6% and 31% +/- 6% in those deemed inoperable (P <.001). Independent risk factors for death were older age (hazard ratio = 1.1; P =.008), previous stroke (hazard ratio = 2.8; P =.003), and being designated an inoperable candidate (hazard ratio = 1.9; P =.04). Actuarial freedom from aortic reintervention and treatment failure at 8 years was 70% +/- 6% and 39% +/- 8%, respectively. Earlier operative year (hazard ratio = 1.2; P =.07), larger distal landing zone diameter (hazard ratio = 1.1; P =.001), and transposition of the left subclavian artery (hazard ratio = 3.3; P =.008) were determinants of treatment failure.
Survival after aneurysm repair using crude, first-generation stent grafts was satisfactory in good operative candidates but bleak in the inoperable cohort, raising the question of whether asymptomatic patients should have even been treated. Late aortic complications were detected in many patients, reemphasizing the importance of serial imaging surveillance.
Journal of Thoracic and Cardiovascular Surgery 03/2004; 127(3):664-73. · 3.41 Impact Factor
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ABSTRACT: Deep venous thrombosis (DVT) has potentially debilitating long-term sequelae if left untreated. Conventional treatment (systemic anticoagulation with heparin followed by coumadin or low molecular weight heparin) often does not adequately relieves clot burden or symptoms, and patients may be left with post-thrombotic syndrome. Although the advent of catheter-directed thrombolysis has markedly improved the treatment of DVT and long-term outcomes of patients treated for DVT, it remains only partially effective on subacute or chronic clot. Mechanical thrombolysis may work synergistically with catheter-directed thrombolysis to decrease clot burden, treatment time, and complication rates, thereby improving outcomes.
Techniques in Vascular and Interventional Radiology 04/2003; 6(1):49-52.
