PubMed Health⌕ Search

Biomedical subjects

P Riggs

Publications and source records attributed to P Riggs.

12 recordsLinked to original sources
PubMed2000

Claviculectomy for subclavian venous repair: long-term functional results.

OBJECTIVES: The purpose of this study was to determine the long-term functional results after medial claviculectomy and venous patch angioplasty or bypass grafting using internal jugular vein after incomplete thrombolysis of effort thrombosis of the subclavian vein. METHODS: The records of 11 patients with effort thrombosis who were treated over the past 9 years were reviewed. Patients have been followed up between 3 and 9 years at 6-month intervals with duplex imaging and contrast venography when indicated and have had an orthopedic evaluation of their shoulder function. RESULTS: All reconstructed veins are patent, and only one patient complains of any arm swelling after prolonged usage. This patient is one of three with postphlebitic changes at the site of repair and has similar findings in her basilic vein. All patients have returned to their prethrombosis vocation without limitation. Four of the 11 patients have jobs requiring heavy physical labor. No patient describes any limitations of shoulder function, but one man who works as a diesel mechanic complains of shoulder aching with overuse with repetitive pulling. Three patients describe upper extremity paresthesias when lying on the operated side. Two patients (one man and one woman) are bothered by the large scar and indentation at the site of the incision. Every patient considers the overall result completely successful from a functional standpoint. CONCLUSIONS: Early subclavian venous repair performed through a medial claviculectomy is a durable operation with excellent long-term functional results. Half of the patients noted minor but significant symptoms, but all are uniformly able to return to normal function.

Adolescent↗
PubMed2000

Expression and purification of recombinant proteins by fusion to maltose-binding protein.

The pMAL vectors provide a method for purifying proteins from cloned genes by fusing them to maltose-binding protein (MBP, product of malE), which binds to amylose. The vectors use the tac promoter and the translation initiation signals of MBP to give high-level expression of the fusion, and an affinity purification for MBP to isolate the fusion protein. The pMAL polylinkers carry restriction sites to insert the gene of interest, and encode a site for a specific protease to separate MBP from the target protein after purification. Vectors with or without the malE signal sequence can be used, to express the protein cytoplasmically for the highest level of production or periplasmically to help in proper folding of disulfide-bonded proteins.

Amylose↗
PubMed2000

Adolescents are not adults: developmental considerations in alcohol users.

Much of the work in adolescent substance abuse assessment and treatment has been a direct transport from tools and modalities used in adult substance use populations. There was a consensus among symposium participants that developmental issues are important in assessment, evaluation, and treatment of adolescents with substance use disorders. These issues directly impact outcome at all levels. Presentations from the symposium may be helpful for conceptualizing the problems of adolescent substance use as well as formulating strategies for future research. Information from the symposium may be viewed as a springboard for future research and clinical intervention in adolescent substance abuse.

Adolescent↗
PubMed1997

Fate of the proximal aortic cuff: implications for endovascular aneurysm repair.

PURPOSE: Long-term success of endoluminally placed grafts for exclusion of abdominal aortic aneurysms (AAAs) relies on secure fixation at the proximal and distal cuffs and, as such, assumes that the fixation sites will not dilate over time. Data regarding this issue, however, are not yet available. This study was performed to evaluate the region of the proximal anastomosis in patients many years after having undergone conventional AAA repair to determine the potential for late dilatation after placement of an endoluminal device. METHODS: Three hundred forty-six patients underwent repair of an infrarenal AAA at our institution between January 1985 and December 1990. Of 97 eligible living patients, 33 both had their original CT scans available and underwent repeat scanning at a mean of 88.6 +/- 23.8 months (mean +/- SD; range, 40 to 134 months) after repair. RESULTS: The overall 5-year survival rate was 73%. The mean preoperative infrarenal aortic cuff diameter by CT scan was 24.5 +/- 3.7 mm (range, 19 to 33 mm). At an average of 89 months after repair, the mean infrarenal aortic diameter increased 4.3 mm to 28.8 +/- 7.7 mm (range, 20 to 52 mm; p = 0.0004 by t test). The proximal cuff at this time measured 30 mm or more in 11 patients (33%), and as early as 6 years after operation three of the seven patients (43%) scanned within this time period had cuffs that were dilated to 30 mm or more. Late dilatation to 30 mm or more was rare (16%) in patients who had preoperative cuffs that measured 27 mm or less. The mean late iliac artery size was 16.9 +/- 8.9 mm (range, 10 to 52 mm), and 30% (10 of 33) measured 20 mm or more. CONCLUSIONS: One third of all patients who survive AAA repair experience significant dilatation of their proximal aortic cuff over time. Proximal dilatation is rare but not absent in patients who have smaller initial aortic cuff diameters. This dilatation rarely causes problems after conventional suture fixation, but the long-term implications of cuff dilatation after endoluminal repair are unclear. Our findings suggest that endovascular aortic prostheses that have the ability to continue to self-expand many years after implantation may be required and that endovascular prostheses may not be the best option for patients who have a long life expectancy or for those who have preoperative proximal cuffs greater than 27 mm.

Aorta, Abdominal↗
PubMed1996

Thrombolysis with prourokinase versus urokinase: an in vitro comparison.

PURPOSE: Despite advantages demonstrated in vitro, no single thrombolytic agent has been clearly shown to be superior to another in the clinical setting. Prourokinase has recently received attention as a new thrombolytic agent with higher fibrin specificity. The thrombolytic activity of prourokinase, however, remains ill defined. The purpose of this study was to evaluate thrombolysis with prourokinase in comparison to urokinase in vitro. METHODS: We used an in vitro parallel channel perfusion model that simulates catheter-directed thrombolysis in the peripheral arterial system. Radiolabeled thrombi were subjected to 90 minutes of endhole catheter-directed infusion with either prourokinase 5000 IU/ml, urokinase 5000 IU/ml; or 5% dextrose in water at 4 ml/hr. RESULTS: Prourokinase and urokinase were found to be equivalent with respect to thrombolytic effect. Percent lysis was maximal at 90 minutes in both the urokinase and prourokinase groups. Prourokinase and urokinase were found to be equally effective in restoring flow through thrombosed graft segments. CONCLUSION: Prourokinase appears to offer little benefit over urokinase with respect to thrombolytic activity in an in vitro model that closely resembles the clinical setting. If prourokinase is to be accepted as an alternative to urokinase, advantages must relate to differences in fibrin specificity.

Catheterization↗
PubMed1995

Thrombolysis in the treatment of lower extremity occlusive disease.

The development of new thrombolytic agents and increased experience in the use of these drugs has enhanced limb salvage, especially in patients who have undergone multiple lower extremity bypass procedures. This article reviews the indications for such therapy and critically assesses both complications and efficacy of treatment.

Arterial Occlusive Diseases↗