235 research outputs found
Data Driven: An Autoethnographic Short Story
In this paper, I use an autoethnographic short story (Jago, 2005, 2011) to examine data-driven life in media culture (Kellner, 1995) and the emergence of a quantified self (Wolf, 2010)
Always a Student of Autoethnography
In this paper, I examine the role of a specific place, Minnehaha Falls in Minneapolis, Minnesota, USA, as a particular grounding space on my autoethnographic journey. I assert this grounding space calls me to remember that I am, and will always be, a student of autoethnography
Change in Everyday Life and in the Communication World: A Co-Constructed Performance Autoethnography
In this paper, we use a co-constructed performance autoethnography to explore change in everyday life and in the communication world
The Writing Exercise: An Autoethnographic Short Story
This paper is an autoethnography about writing as a form of communication in the age of new media
Effects of dietary L -arginine on structure and function of flow-restricted vein grafts
AbstractPurpose: Experiments were designed to determine effects of dietary supplementation with L -arginine on structure and function of flow-restricted vein grafts. Methods: Saphenous veins were placed as bilateral interposition grafts in femoral arteries of two groups of adult male mongrel dogs; one group was maintained on a normal diet (control), the other group supplemented with L -arginine (200 mg/kg per day) beginning 1 week before surgery. In each dog, flow was reduced by 50% in one graft by placing an adjustable clamp on the artery distal to the distal anastomosis. Plasma amino acids and oxidized products of nitric oxide (NOx ) were measured before and after L -arginine feeding. At postoperative week 4, grafts were removed and prepared for organ chamber studies to determine functions of the endothelium or smooth muscle and for histology. Results: Plasma L -arginine increased within 3 hours after feeding and increased from 141 ± 8 nmol/mL to 169 ± 11 nmol/mL (n = 6) after 5 weeks of supplementation. Plasma ornithine and citrulline paralleled arginine, whereas circulating NOx was unchanged. Maximal contractions to 60 mmol/L KCl were reduced in grafts from L -arginine–fed dogs. Endothelium-dependent relaxations to the calcium ionophore A23187 and relaxations of the smooth muscle NO were reduced in grafts from L -arginine–fed dogs. Neointimal hyperplasia was increased in grafts with reduced flow and not affected by arginine feeding. Conclusions: Dietary supplementation with L -arginine did not increase plasma NO in dogs with peripheral vein grafts or increase endothelium-dependent relaxations in control or flow-restricted grafts. Therefore, dietary supplementation with L -arginine may not improve long-term functions of flow-restricted peripheral bypass grafts. (J Vasc Surg 2001;33:829-39.
Urokinase treatment preserves endothelial and smooth muscle function in experimental acute arterial thrombosis
AbstractPurpose: Pharmacologic lysis or balloon thrombectomy are options to treat acute arterial thrombosis; however, little is known about their effects on functional changes in the arterial wall. The aim of this study was to determine function of the endothelium and smooth muscle in canine arteries revascularized after acute thrombosis with balloon thrombectomy or lytic therapy.Methods: Acute thrombosis was obtained by bilateral proximal and distal ligation of 8-cm segments of the femoral arteries in dogs. After 24 hours, the ties were removed and the arteries randomized to treatment groups: group 1, balloon thrombectomy (#4 Fogarty balloon catheter at 60 grams linear shear × 1 pass, n = 7); group 2, untreated, tie removal only (n = 6); group 3, regional intra-arterial urokinase infusion (4000 U/min × 90 min, n = 6); group 4, regional intra-arterial carrier infusion (0.43 ml/min × 90 min, n = 6); group 5, unoperated normal vessels (n = 5). After treatment, the arteries were removed and endothelial and smooth muscle responses examined in organ chambers. Endothelial loss was graded with light microscopy of vessel rings from each animal by an observer blinded to the treatment group. Findings were confirmed with scanning electron microscopy.Results: Treatment with urokinase did not alter endothelium-dependent relaxations or smooth muscle contractions compared with carrier infusion or untreated alone. Balloon catheter thrombectomy significantly reduced endothelium-dependent relaxations compared with all other groups in response to acetylcholine, bradykinin, and thrombin (p < 0.001). Contractions of smooth muscle in response to potassium chloride (60 mol/L) and phenylephrine (1 × 10-6 mol/L) were also reduced (p < 0.05). Rings from balloon thrombectomized arteries contracted in response to calcium ionophore A23187 (p < 0.001); these contractions were endothelium dependent and not reduced by indomethacin or blockade of endothelin A and B receptors. No significant differences in percentage of endothelial coverage between groups were assessed by light and electron microscopy.Conclusion: Thrombolysis with urokinase caused no or minimal abnormalities in endothelial and smooth muscle function. Endothelium present after balloon thrombectomy produces contractile factors. Although the duration and recovery of these abnormalities in function are unknown, these findings support preferential use of urokinase over balloon thrombectomy when possible in acute arterial thrombosis or embolism. (J Vasc Surg 1996;23:851-9.
Surgical technique and preliminary results of endoscopic subfascial division of perforating veins
Purpose: Direct surgical ligation of incompetent perforating veins has been reported to effectively treat severe chronic venous insufficiency. It is associated, however, with significant wound complications. We evaluate our early experience with endoscopic subfascial division of the perforating veins.Methods: From August 5, 1993, to December 31, 1994, 11 legs in nine patients (five male and four female) were treated with endoscopic subfascial division of perforating veins. Nine of the 11 legs had active or recently healed venous ulcers. Mean duration of the ulcerations was 5.6 years. Standard laparoscopic equipment with two 10-mm ports was used to perform clipping and division of medial perforating veins through two small incisions made just below the knee, avoiding the area of ulcer and lipodermatosclerosis. Carbon dioxide was insufflated at a pressure of 30 mm Hg into the subfascial space to facilitate dissection, and a pneumatic thigh tourniquet was used to obtain a bloodless operating field. Concomitant removal of superficial veins was performed in eight limbs. Mean follow-up was 9.7 months (range, 2 to 13 months).Results: A mean of 4.4 perforating veins (range, 2 to 7) were divided; tourniquet time averaged 58 minutes (range, 30 to 72). Wound infection of a groin incision and superficial thrombophlebitis were early complications; each occurred in one patient. In seven legs the ulcer healed or did not recur and symptoms resolved. In three legs the ulceration improved, and in one it was unchanged.Conclusions: Endoscopic subfascial division of perforating veins seems to be a safe technique, with favorable early results obtained in a small number of patients. This preliminary experience supports further clinical trials to evaluate this technique
Inflammatory abdominal aortic aneurysms: A case-control study
AbstractPurpose: This study was designed to identify significant differences in the clinical and radiologic characteristics and outcome between patients with inflammatory and noninflammatory abdominal aortic aneurysms (AAAs).Methods: We reviewed 29 consecutive patients who underwent repair of an inflammatory AAA between 1985 and 1994. This group was matched in a case-control fashion by date of surgery and by the performing surgeon to a group of 58 patients who underwent repair of noninflammatory AAAs.Results: The two groups had comparable characteristics of age, gender, and cardiovascular risk factors. Patients with inflammatory AAAs were significantly more symptomatic than those with noninflammatory AAAs (93% vs 9%, p < 0.001), were more likely to have a family history of aneurysms (17% vs 1.5%, p = 0.007), and tended to be current smokers (45% vs 24%, p = 0.049). Thi most significant laboratory difference was an elevated sedimentation rate in patients with inflammatory AAAs (mean, 53 mm/hr vs 12 mm/hr, p < 0.00001). Inflammatory AAAs also were significantly larger than noninflammatory AAAs at presentation (6.8 cm vs 5.9 cm, p < 0.05). Although operative mortality was low in both groups, patients with an inflammatory AAA tended to have higher morbidity, including sepsis ( p < 0.01) and renal failure ( p = 0.04). Five-year survival rates, however, were similar for the two groups (79% for inflammatory and 83% for noninflammatory AAAs). On follow-up computed tomographic scans, the retroperitoneal inflammatory process resolved completely in 53% of the patients, but 47% of patients had persistent inflammation that involved the ureters in 32% and resulted in long-term solitary or bilateral renal atrophy in 47%.Conclusions: This case-control study provides preliminary evidence that inflammatory AAAs may have a relatively strong familial connection and that current smoking may play an important role in the inflammatory response. The study also documents that persistent retroperitoneal inflammation may be more prevalent than has been previously reported, and stresses the need for an improved understanding of the pathogenesis and long-term management of inflammatory AAAs. (J Vasc Surg 1996;23:860-9.
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